Cycling With Or Without Plants - Debating The Merits Of Each

[three-fingers]

I would remove it! Supplementing carbon will mean the plants have a higher demand for other nutrients too, what fertilisers are you giving your plants?
 
You cant really cycle a planted tank in the same way as a non-planted tank, as the plants just use up the ammonia as a nitrogen source instead of the bacteria.
 
If you have a planted tank - focus on getting the plants healthy and growing for a few weeks before gradually stocking tank with fish.  This means research into water flow, fertilisers and light and monitoring CO2.  The plants will take care of the water quality, not the filter.  Instead of reading up on cycling, you should be reading here

: Planted Aquarium Resource Centre.
 
If your not really set on having a fully fledged planted tank, then cycle the tank without the plants or CO2, then add the plants back when cycling.
 
See here: Why We Should Not Fishless Cycle Planted Tanks.

 

[TwoTankAmin]

I disagree with the last piece of advice in the above post.  Obviously, I should mention that I disagree with a bunch of what is in the article on why not to fishless cycle planted tanks. I think a lot of what is in it is incorrect. But that is one fish keeper's opinion.
 
Plant the tank, then cycle it. Because plants consume ammonia, They reduce the amount of bacteria a tank might need to handle its full stocking. This mean that given two identical tanks except one has live plants and the other does not, it will require more bacteria in the tank without plants to handle any given bio-load. This tank will require 5-6 weeks to cycle. But the planted version will be cycled in much less time.
 
Both tanks would be dosed with ammonia et.c as in fishless cycling. But the planted tank will be able to process all the ammonia well before the unplanted tank. There is a further benefit to this. While waiting to build up whatever bacteria may be needed, the new plants will be working to root in the substrate of to attach to wood/rocks etc. This will keep them in place when fish might dislodge and/or uproot them. I would even suggest one plant the tank, wait about 10 days and then start to cycle it the rest of the way without fish
 
If you 1st cycle a tank and then plant it you greatly increase the time it takes from start to full stocking. I have followed this method for many years now and used it on numerous tanks with great results. However, it is important to use the lower levels of ammonia recommended in the cycling article here. This helps to minimize or reduce the potential for algae.
 
With heavily planted tanks there is usually little or no need to cycle, especially if one is prepared to add fish gradually rather than wanting to stock fully all at once. Moreover, one needs to be cautious fertilizing newly transplanted plants, especially if using substrate fertilizer. There is always a risk to new roots of fertilizer burn.

 

[three-fingers]

Plant the tank, then cycle it. Because plants consume ammonia, They reduce the amount of bacteria a tank might need to handle its full stocking. This mean that given two identical tanks except one has live plants and the other does not, it will require more bacteria in the tank without plants to handle any given bio-load. This tank will require 5-6 weeks to cycle. But the planted version will be cycled in much less time.

This is the part I have to disagree on - the planted tank could either be cycled faster as you describe, it could partially cycle and then stall, or it more likely it just wont cycle wont cycle as the article discusses. Either way, for a beginner, its going to make the cycle more complicated as you wont be able to rely on the water tests showing that you have an established bacterial population - if ammonia disappears, it could be 50% plants 50% bacteria that are processing the ammonia or 100% plants - who knows. How much ammonia the plants consume would vary greatly on so many factors - how established the plants are in the tank, the levels of various nutrients in the tank (which would change daily), how much light the plants are receiving, what algae species they have to compete with ect.
 
There is no way of telling, too many variables to account for that would be changing all the time, especially difficult for a beginner to judge what the test results mean! 
 
Seems to me to defeat the purpose of a controlled fishless cycle, if your going to have a planted tank, why not just get the plants growing well then add the fish afterwards? Much safer for the fish and plants, plus saves loads of time.
 
If your priority is to have pet fish, as opposed to a fully planted tank, then save all of the above guesswork and complications, remove the plants, and get on with the cycle knowing that you are growing bacteria, not plants! That way all your fish wont die if you make a mistake with the plants, leaving you with an insufficient bacterial colony.
 
You can add plants after you are sure you have a mature bacterial colony, if you want to do a cycle.

If you 1st cycle a tank and then plant it you greatly increase the time it takes from start to full stocking.

I'm not sure I understand you here, this seems to contradict what you said above - that tanks with plants in them can process more ammonia.  Adding plants is like adding an instant bio filter - how could this possibly mean you have to stock the tank slower?  Adding loads of plants to a freshly cycled tank will obviously reduce the levels of bacteria, but fish don't care as long as the water is free from ammonia. This does defeat the purpose of doing the cycle in the first place, as I have mentioned above, this is why I think its silly to cycle a tank if you aim to have it planted - you are just wasting time!  You would be much better spending time reading about how to keep plants healthy.

 

[TwoTankAmin]

Again- this is not correct
 

 
Either way, for a beginner, its going to make the cycle more complicated as you wont be able to rely on the water tests showing that you have an established bacterial population - if ammonia disappears, it could be 50% plants 50% bacteria that are processing the ammonia or 100% plants -

 
If the plants are doing 100% of the ammonia processing, there is no need for bacteria at all. If the plants are handling 1/2 the ammonia, then bacteria will colonize to handle the rest.
 
It does not matter how much of the bio-load is handled by plants or by bacteria, all that matters is it is handled. So here is what you do:
 
1. Set up and plant the tank and give the plants time to establish.
2. Dose ammonia into the tank to 3 pm.
3. Test in 24 hours. 
3b. If ammonia is 0, the plants are handling all the load, no bacteria are needed and you can add fish.
3c. If you get an ammonia reading, proceed as if doing a normal fishless cycle according to the directions.
4. If you are willing to add fish gradually, reduce the ammonia dose to 2 ppm or even 1.5 ppm from the normal 3 ppm and proceed as in step 3s above.
 
Let me explain why I say "If you 1st cycle a tank and then plant it you greatly increase the time it takes from start to full stocking."
 
To do a fishless cycle dosing to 3 ppm of ammonia takes about 5-6 weeks. Then you add plants and have to wait a week to 10 days for them to establish before adding fish. So now from start to finish you are taking 7-8 weeks to be fully stocked. Plant the tank and wait the same week to 10 days and then start to add ammonia at 3 ppm according to the cycling directions here. Now lets assume you have plants sufficient to handle 1 ppm of ammonia. This means the amount of bacteria needed is what it take to process 2 ppm and not 3 ppm. The less bacteria one needs, the less time it takes to reach that level. Now if you plant enough to handle 1.5 or 2 ppm the fishless part becomes really quick.
 
Of course I have not mentioned that fact that live plants have bacteria on them especially the root. So they act to seed a tank some. So in addition to the benefit of having plants that eat ammonia, you have seeding some bacteria which also speeds one's cycle.
 
Like I said that article is way off the mark.
 
There is absolutley no way planting a tank can stall a cycle.

 

[three-fingers]

If the plants are doing 100% of the ammonia processing, there is no need for bacteria at all.

Agreed. Therefor, if you have a tank full of plants you intend to keep healthy, theres no need for a cycle. Trying to cycle a tank that can have 100% of its ammonia processed by plants is mainly just wasting time you could be spending trying to get healthy plants, and potentially encouraging algae growth or damaging plants with high ammonia. 
 

If the plants are handling 1/2 the ammonia, then bacteria will colonize to handle the rest.

Not necessarily, because as I explained above, too many different factors affect plant health, which in turn affects ammonia uptake. The first day the plants may be up taking 50% of the of ammonia, the 2nd day of the cycle maybe 25%  and next day it could be 75%.  Unless you are doing all you can to ensure the plants are totally healthy, theres no way to estimate how much the plants are taking up compared to the bacteria.  It would be total guesswork (especially for a beginner) how much bacteria you have at the "end" of your cycle, and this could obviously be disastrous for a beginner.

It does not matter how much of the bio-load is handled by plants or by bacteria, all that matters is it is handled. So here is what you do:

Agreed, but rather than follow those steps, I would prioritise just one method to get right - plants or bacteria - rather than complicating things.  Doing both at the same time will give inconsistent results. Totally defeats the point of doing a cycle! (to be sure the tank is ready for fish).
 
You say to dose the tank with 3ppm and if its all gone, then no bacteria are needed, I would agree. However, if some ammonia is left, adding more ammonia to do a cycle will just waste time. If your willing to rely on plants rather than a biofilter in the first place, then do just that and focus on keeping plants healthy rather than making them get their nitrogen from toxic ammonia which encourages algae and can damage plants.  The cycling process will hinder plant growth, and the plant growth will hinder bacterial growth. Why bother trying to grow both at the same time?
 
I would only bother fishless cycling if I wasn't confident I could keep plants healthy enough to process the ammonia, in which case I would want to do the fishless cycle properly without plants and know that the bacteria had been processing the ammonia so I could at least be confident my biofilter was working.
 

There is absolutley no way planting a tank can stall a cycle.

I was very surprised to read this statement! I was under the impression it was common knowledge that this could happen. Just Google "plants stall cycle" and you will find plenty of evidence on aquatic forums that this can happen

. "Cycling" a tank is the process of growing nitrogen processing bacteria - plants compete with these bacteria. Adding plants could easily stall or stop tank cycling entirely, as discussed above.
 
To the OP - I'm sorry if our discussion here is confusing things!
 
I would suggest that you stick to the planted forums if a planted tank is your aim (which I guess it is since you've invested in CO2) . It's my opinion for all the reasons stated above (and certainly the prevailing opinion in the planted/aquascaping hobby - so hopefully someone else will chime in here) that fishless cycling a tank with plants is  going to totally confuse and mess up your cycling results, while also encouraging algae. 

 

[TwoTankAmin]

Three, I think you need to read my posts several times before you reply.
 
So go back and reread what I said an respond to it and not something you think I said. If you dose the 3 ppm and it goes to 0 in 24 hours I said you were cycled. I said if it failed to go to zero then from that pint on finish up as if you were well into a fishless cycle. So read the article on fishless cycling on this site to understand what that means. I said to plant first and wait to let the plants settle in, at this point they will be processing ammonia at a fairly steady rate. And lets not forget that fish do not wake up, dump 3 ppm of ammonia and that's it for the day. They produce it at lower levels 24/7. The plants will never have to take up that much ammonia all at once in an established tank.
 
Further, there is simply no connection between the health of the  bacteria and the plants except that when both are present, plants take up ammonia faster than bacteria. If there is ammonia left over, then the bacteria will develop to the level needed to handle that excess. If there is not, no bacteria will colonize. If you add enough ammonia to a new tank with plants to kill the plants, it will also prevent the Nitrosomonas from colonizing. At best you would get the strains that function in waste water treatment and sky high ammonia. These do not survive longer term in tanks where ammonia is much lower.
 
Cycling is the process of developing sufficient bacteria to handle the waste in a tank. the less waste, the less bacteria. The more plants, the less waste so the fewer bacteria that are needed. They work together not in competition. And you do not have to know exactly how much the plants are taking up, although I did explain how to know, you dose and test.
 
But let me leave it at this. I have cycled about 35-40 tanks or possibly a few more as I have described above. Some were heavily planted, some moderately and some minimally.have never had an problems or issues doing this. I have cycled a similar number of tanks with out plants. there is simply mo connection between the bacteria and the plants except that when both are present, plants take up ammonia faster than bacteria. If there is ammonia left over, then the bacteria will develop to the level needed to handle that excess.
 
I have one final question. I set up a tank and I plant it moderately. I do not have enough plants in it to handle all the ammonia. So this means I also need some bacteria to handle the ammonia. How will I know when the tank is cycled? The answer is the exactly same way I would know when a tank without plants is cycled. You do not count bacteria, you test the ammonia and nitrite and when they read 0, you are cycled. If plants handle 100% of the ammonia, the tank is, in effect, cycled, if they do not, ammonia is left over and the tank is not cycled. It will need to develop some level bacteria to reach that level. And how do you know it has reached that level? You test until you see 0/0.
 
So what are you going to tell somebody who wants a lightly or moderately planted tank? Don't do it because the plants and bacteria will fight? If you get it right, you are going to tell them exactly what I have written above.
 
I do not care what some sites say about plants stalling a cycle, it simply is not true. Nor do bacteria take away anything from plants. You might want to read these papers:
 
Reconciling water quality parameters impacting nitrification in aquaponics: the pH levels
http/fshs8813.wpengine.com/proceedings-o/2004-vol-117/079-083.pdf
or
Reconciling pH for Ammonia Biofiltration and Cucumber Yield in a Recirculating Aquaponic System with Perlite Biofilters
http/hortsci.ashspublications.org/content/43/3/719.full
 
The above are research into the use of plants and nitrifying bacteria in concert and how ammonia is handled.

 

[three-fingers]

*Deep breath*
  

Three, I think you need to read my posts several times before you reply

I believe you need to do more research on planted tanks . Try posting that advice in any reputable planted aquarium forum and you would be jumped on immediately by multiple users correcting you.  What I'm saying is common knowledge in planted communities, its just obviously not caught on here yet.  Well, it has in the planted section anyway, years ago even, hence the article I posted by a well reputed member.
 

 So go back and reread what I said an respond to it and not something you think I said

That's why I go through the effort of quoting

.  I have read and understood everything you've said, and I can totally see where your logic is coming from having much experience on the fishy side of things, unfortunately I just think your wrong with regard to planted tanks. 
 
On the subject of not reading ones posts....
 

If you dose the 3 ppm and it goes to 0 in 24 hours I said you were cycled

Um, no you didn't, you said if it goes to 0ppm  "the plants are handling all the load, no bacteria are needed". In other words, there is no established bacteria colony, and you are not cycled. Of course, as we seem to agree, the amount of bacteria doesn't matter if you have enough healthy plants - which is why its a waste of time trying do a fishless cycle in such a tank.
 
Going through the expense of getting live plants and a CO2 kit, and then dosing high levels of ammonia into the tank?! Madness!

  Unless you are trying to grow algae of course.
 

 
I said if it failed to go to zero then from that pint on finish up as if you were well into a fishless cycle. So read the article on fishless cycling on this site to understand what that means.

 You said "proceed as if doing a normal fishless cycle", which is bad advice for a planted tank, for the reasons I keep repeating. If you meant to say "finish up as if you were well into a fishless cycle" (which you didn't), well, you'll need to clarify what you mean as its an ambiguous sentence. "Finish up" as in...proceed to the last step?  Or "finish up" as in continue to test, add ammonia and do water changes? How far into a cycle is "well into"? 

I've read your article, its a well written article, clearer than the previous ones on the forums. I understand the process and have used it a few times before (just out of curiosity to test bottled bacteria effectiveness), and have been reading and posting about cycling on this forum for the past 7 years

.
 

I said to plant first and wait to let the plants settle in, at this point they will be processing ammonia at a fairly steady rate.

That's a MASSIVE assumption!

Considering every tank is different in many ways, and the hundreds of different species of plants available to hobbyists. Ammonia is more toxic to some plants than others, and the swinging ammonia levels alone will mean huge variance in uptake levels. Not to mention temperature,  pH and other nutrient levels will vary by the hour and will have a huge effect on plants nutrient uptake.
 
You may find a book like Diana Walstad's "Ecology of the Planted Aquarium" a very interesting read, it sheds light on a lot of the known chemical and biological processes that are going on in planted tanks, and shows their effect on plant growth, all referenced with studies.
 

The plants will never have to take up that much ammonia all at once in an established tank.

I never suggested that anyway, but of course plants don't uptake nutrients all at once, they do it gradually, and with different efficiency depending on the ammonia ppm and countless other factors depending on the species.
 

Further, there is simply no connection between the health of the  bacteria and the plants except that when both are present, plants take up ammonia faster than bacteria.

Well, while that is the only connection I was implying in my post anyway..., that is a hugely sweeping statement. I'm not going to get into the different relationships various nitrogen consuming bacteria and plants have with each other. As I thought we agreed (or not, given your last post)...they both compete with each other for ammonia, plants can take it up faster in general, but this uptake depends on so many factors that vary during a cycle that you simply cannot say that's the case during the cycle.  As I've explained, plant uptake may be 25% of the ammonia on day one, 75% day two, 50% day three. It may vary by the hour. This will in turn negatively affect the establishment of a bacterial colony, as on some days the bacteria grow, some days they may die. You want stable conditions for cycling, plants complicate things.
 

If you add enough ammonia to a new tank with plants to kill the plants, it will also prevent the Nitrosomonas from colonizing.

 
Nope, not necessarily at all. Not all plants are remotely equal in their ability to tolerate/uptake ammonia. There are HUGE documented variances even among related species of common aquarium plants. For example in a study, Egeria canadensis was shown to have a 20% reduction of photosynthesis when exposed to 3.2ppm ammonia, while Egeria nuttallii showed no observable change even at 9ppm.  For some plants, 0.5ppm could potentially stunt growth just enough to let algae take over, spelling eventual doom for the plant. Some can tolerate higher levels, it just depends on their evolutionary history.
 
And remember its not just certain ppm at which ammonia suddenly becomes toxic - lower levels have a chronic effect on plants just like fish.  To complicate things further, various algae LOVE ammonia, and an algae outbreak could easily kill all the plants depending on the species. 
 
I've got to change the format of my reply now as apparently I've used too many quote boxes  

 .
 
"They work together not in competition. And you do not have to know exactly how much the plants are taking up, although I did explain how to know, you dose and test."
 
I don't know why you think this, the bacteria are not in a symbiotic relationship with the plants here, they are mainly tucked away in the filter, very much competing with the plants for nitrogen.  How can two living things use the same limited recourse and not be competing?

 They cant. The plants and bacteria in our aquariums are a perfect example of competition.
 
What I said you could not measure is how much the plants are taking up compared to the bacteria, obviously you can easily test the total ammonia consumed, but that's a useless measurement as you have no idea if its just because your plants are happy, or if you have an established bacterial population.
 
"But let me leave it at this. I have cycled about 35-40 tanks or possibly a few more as I have described above. Some were heavily planted, some moderately and some minimally.have never had an problems or issues doing this. I have cycled a similar number of tanks with out plants."
 
You may think you cycled the tanks, what I'm telling you is that you have no way of really knowing what actual biological processes were going on in the tanks. You are just guessing based on experience. It may work very well for you, I'm sure you know what you are doing. But to advise an inexperienced beginner to take a similar approach is asking for trouble. On a CO2 enriched (i.e. high-tech) tank - adding ammonia is a recipe for a huge algae bloom and dead plants. I've only got to assume you've not had much experience with high-tech planted tanks, if you had you would know that what I'm saying is common knowledge nowadays.
 
I've probably set up a similar number of tanks to you over the years, including quite a few high-tech planted tanks. I've never fishless cycled a planted tank before adding fish - I don't see the point. plants Nobody wastes time cycling planted tanks in the planted tank community. There are no cycling articles for beginners on the specialist planted forums. Its very widely accepted to be detrimental to setting up a planted tank, or at best just a huge waste of time. 
 
"If plants handle 100% of the ammonia, the tank is, in effect, cycled, if they do not, ammonia is left over and the tank is not cycled. It will need to develop some level bacteria to reach that level. And how do you know it has reached that level? You test until you see 0/0."
 
If you have such a tank, you should try to get the plants growing healthy enough until they can consume 100% of the ammonia - not add more ammonia!  If your plants need
nitrogen for growth, give them some KNO3 or other nitrate based fertiliser instead of ammonia. Ammonia will just hurt the plants - to varying degrees - and encourage algae to compete with the plants.
 
"I do not care what some sites say about plants stalling a cycle, it simply is not true. Nor do bacteria take away anything from plants. You might want to read these papers:"
 
You should care, because many of those sites are written by people with far more experience than you with planted tanks.
 
Those studies only relate to aquaponics (terrestrial plants with their roots in the water) - an interesting subject irrelevant to our discussion here of submersed aquatic plants in high-energy aquatic ecosystems. Aquatic plants mainly uptake nutrients through the leaves using completely different processes.  Not to mention algae isn't a factor in aquaponics like it is in aquariums.
 
"So what are you going to tell somebody who wants a lightly or moderately planted tank? Don't do it because the plants and bacteria will fight?"
 
I would tell them what I have already advised above: add the plants AFTER doing the cycle, otherwise it will massively complicate the fishless cycle, possibly damage your nice new plants and you will have to deal with lots of algae...
 
I'm still advising the OP to go to the planted forum (or maybe even UKAPS) for further advise if its a planted tank they want, or  just ditch the CO2 and plants until they have mastered the basics of keeping a fish tank using a biofilter. 

 

[TwoTankAmin]

Once again you are not listening. You are operating under the assumption is there are two kinds of tanks involving live plants- heavily planted or not planted at all.
 
You, and most plant mavens, fail to deal with the myriad number of tanks out there that have live plants but will never be heavily planted. In fact I would venture that the great majority of tanks which contain live plants are not heavily planted. You are also ignoring the fact that adding live plants seed bacteria into a tank. So exactly how do you know when you set up the tanks you refer to contain bacteria or how much? Are you saying that all this seed bacteria dies in a tank with plants? While it is nice to claim that the plants are handling all of the load, exactly how can you prove this? The only way i can think of would be the standard methods of assessing bacteria involving DNA, AMO, FISH analysis etc. The same methods used in most research into nitrifying bacteria
 
But I do not accept your telling me what is on planted tank sites nor especially plant sub-forums on general sites. Quote some real science if you want folks to believe that plants and bacteria compete in a way that creates any issues in tanks. In fact, if you were accurate in this respect then how do you account for the two studies I linked to above where bio-filtration and hydroponics are joined to operate more efficiently than either alone?
 
As far as I can tell, there is no competition between plants and bacteria in regards to handling the job of processing nitrogenous wastes in aquariums. If you have enough plants to process all the bioload, there is no need for any bacteria, but does this mean there is none at work at all? If you have a tank 100% cycled by bacteria, then there is no need for plants to do any of this work. These are the two extremes of a scale. But there are a ton of situations where the "cycling" duties are handled by a combination of bacteria and live plants. If plants and bacteria can not work in concert, how do all these tanks exists and not kill or harm the fish?
 
And then there is the fact that ammonia exists in 2 forms NH3 and NH4. As long as the pH of a tank is in the 6.5 or higher range, some ammonia is in both forms. But this is where it gets interesting. The bacteria take up NH3 but the plants take up NH4. As long as there is any total ammonia in a tank and the pH is 6.5 or above, there will be both forms present. And as the pH and temp rise, more of the total ammonia is in the NH3 form. So unless live plants can instantly consume 100% of any ammonia as it is being created, there will be NH3 present and there will be bacteria taking advantage of that.
 
But lets touch on one part of this discussion that has been omitted completely. It as stated its too complicated for a newbies to grasp what I am saying and to do what I suggest. Yet there is no problem regarding acomplete newbie to take their first step into live plants at the most sophisticated and complex level possible with no experience in live plantsat all. To me this is akin to telling a newbie that the first fish they can keep are wild altum angels. I liken getting into live plants that way as one's learning to drive for the first time in an Indy 500 race car. Imo, learning how porperly to manage a high light, co2 added regularly fertilized tank is not exactly easy.
 
As for folks on plant sites having any real knowledge about the bacteria and the nitrogen cycle, I am dubious. On these sites they also tell us that if the bacteria do not get ammonia for a week they will all die- another urban aquarium myth.
 
If you wish to propose that idea that nitrification and aquatic plants interfere with each other under normal conditions, all I would like is scientific and not anecdotal evidence of this. What is the biology and chemistry that causes it. What I see on the plant sites is they say plant up the tank heavily with stem plants, wait about 2-4 weeks and add fish slowly. There is little difference between this and a fish in cycle in terms of time. And it is useless advice for those who have no desire to have heavily planted tanks but want some level of live plants.
 
One last observation, here is a quote from Tom Barr:

 
Add lots of plants, they directly take up NH4, adding CO2 amplifies the uptake of NH4 by about 5-10X, also amplifies algae growth as well

from http/www.barrreport.com/showthread.php/3304-What-is-the-best-way-to-cycle-a-planted-tank
 
So he is saying that, without any ammonia addition to a new planted tank, the addition of co2 will amplify algae growth. Interesting......

 

[eaglesaquarium]

I've split this off into a separate discussion, as something tells me that it isn't helping the OP, but it is a worthwhile discussion to have.


I only ask that it remain civil.

 

[three-fingers]

Thanks, I think we scared the OP off, but I hope the discussion will be useful for future readers  . No probs

 .
 

Once again you are not listening. You are operating under the assumption is there are two kinds of tanks involving live plants- heavily planted or not planted at all.

 

Quote just one place I have suggested this.... . Please stop telling me I'm not listening. If you think I've missed something you have typed, re-state it like I have had to do with all of my points, and I will patiently reconsider what you have said .
 
Of course there are loads of tanks in between, I'm not operating on that assumption at all. What I'm suggesting is that beginners should chose one type of tank to start with, planted, or not and follow the recommended procedures.  These being either fishless cycling, or doing all you can to create healthy plant growth. It keeps things simple and avoids all of the complications I have repeated several times in my above posts.
 

You, and most plant mavens, fail to deal with the myriad number of tanks out there that have live plants but will never be heavily planted. In fact I would venture that the great majority of tanks which contain live plants are not heavily planted. You are also ignoring the fact that adding live plants seed bacteria into a tank. So exactly how do you know when you set up the tanks you refer to contain bacteria or how much? Are you saying that all this seed bacteria dies in a tank with plants? While it is nice to claim that the plants are handling all of the load, exactly how can you prove this? The only way i can think of would be the standard methods of assessing bacteria involving DNA, AMO, FISH analysis etc. The same methods used in most research into nitrifying bacteria

Fail to deal with? In what way?  I suggested tanks that are not to be heavily planted should be fishless cycled according to procedure, and then plants can be added once that procedure is taken care of. Seems a perfectly good way to deal with such tanks to me.
 
I'm ignoring that fact because its moot to our discussion. The bacteria that hitchhike on plants will obviously "seed" the tank, but then so would a small pinch of dirt from your garden.  If you want to seed a tank with bacteria for a fishless cycle, live plants are a poor choice of carrier, because like I keep saying,  they will compete with the bacteria for the ammonia.
 

But I do not accept your telling me what is on planted tank sites nor especially plant sub-forums on general sites. Quote some real science if you want folks to believe that plants and bacteria compete in a way that creates any issues in tanks. In fact, if you were accurate in this respect then how do you account for the two studies I linked to above where bio-filtration and hydroponics are joined to operate more efficiently than either alone?

I'm sorry you  "don't accept" me telling you what info is on other websites lol. I'm not even sure if your not accepting my assertion that the information is there, or if your not accepting the validity of the information I am referring to.
 
"Real science" (I presume you mean published papers) on the subject of plant and bacteria competition with relation to algal growth and plant health within aquariums? Are you joking, who would fund that? There are looooads of articles and forum posts by chemists, biologists and professional aquarists out there though.  Obviously I cant link to discussions son other forums due to the forum rules.  The "real science" I am trying to explain to you is a very basic and sound concept within biology called "competitive exclusion".  Your only contradicting yourself saying that they don't compete with each other, despite using the same limited resource.  That's the definition of the term...
 
How do I account for the studies you linked to?  I don't need to, for the reasons I have already stated, those studies are totally irrelevant to our discussion. If you still feel otherwise, please try to explain in detail why you think comparing terrestrial plants growing with their roots underwater in the dark to aquatic plants that uptake their nutrients mainly through their leaves underwater in high-light conditions is useful to this discussion. 
 
Terrestrial plants usually have well documented symbiotic  relationships with various fungi and algae in the aerobic substrate environments. This symbiosis does not occur on aquatic plant leaves, where the plants directly uptake nutrients without any help from bacteria.  And aquatic substrate environments are usually anaerobic, so most plants growing underwater won't benefit from the symbiosis documented in those papers.
 
What's more, as I've said before, the aquatic plants have to compete with algae as well.
 

As far as I can tell, there is no competition between plants and bacteria in regards to handling the job of processing nitrogenous wastes in aquariums. If you have enough plants to process all the bioload, there is no need for any bacteria, but does this mean there is none at work at all? If you have a tank 100% cycled by bacteria, then there is no need for plants to do any of this work. These are the two extremes of a scale. But there are a ton of situations where the "cycling" duties are handled by a combination of bacteria and live plants. If plants and bacteria can not work in concert, how do all these tanks exists and not kill or harm the fish?

As already stated countless times - of course there is competition. If you still don't think so, how would you define "competition"?  Plants and bacteria do not "work in concert", that's simply a poor analogy that doesn't apply to the situation we are discussing. In the root systems of most terrestrial plants, you could say that the bacteria and plants "work in concert" as a rough analogy meaning they have a specific symbiotic relationship with each other.

And then there is the fact that ammonia exists in 2 forms NH3 and NH4. As long as the pH of a tank is in the 6.5 or higher range, some ammonia is in both forms. But this is where it gets interesting. The bacteria take up NH3 but the plants take up NH4. As long as there is any total ammonia in a tank and the pH is 6.5 or above, there will be both forms present. And as the pH and temp rise, more of the total ammonia is in the NH3 form. So unless live plants can instantly consume 100% of any ammonia as it is being created, there will be NH3 present and there will be bacteria taking advantage of that.

Um...no, sorry, that doesn't make any sense. As you say, NH3 and NH4 exist in equilibrium with each other. This means that if the plants keep up-taking NH4, the NH3 levels will drop too, relative to the amount of NH4. Therefor, the plants can effectively reduce/remove all of the NH3 levels.
 
Besides, the plants can directly uptake NH3 if their nitrogen demand was high enough, they just prefer NH4.
 
In a tank that's stocked with fish as opposed to dosed with ammonia, its even simpler. Depending on stocking and planting levels, the plants could potentially consume all of the urea from the fish before it even gets broken down into by bacteria into NH3/NH4!  I'm not arguing that he bacteria aren't present, I've never once implied that.
 
I'm simply saying that in the very unstable and variable conditions of a planted tank that someone is trying to fishless cycle, the bacteria will be hindered by competition for ammonia with the plants (and all other nutrients for that matter).
 

But lets touch on one part of this discussion that has been omitted completely. It as stated its too complicated for a newbies to grasp what I am saying and to do what I suggest. Yet there is no problem regarding acomplete newbie to take their first step into live plants at the most sophisticated and complex level possible with no experience in live plantsat all. To me this is akin to telling a newbie that the first fish they can keep are wild altum angels. I liken getting into live plants that way as one's learning to drive for the first time in an Indy 500 race car. Imo, learning how porperly to manage a high light, co2 added regularly fertilized tank is not exactly easy.

That's just another bad analogy. High-tech tanks and following modern advice on planted tanks is not "the most sophisticated and complex level" at all. It may seem that way to you, because you don't currently don't understand the behind the biological processes, but the modern equipment and advice actually make it much easier to set-up and maintain a planted tank. Compromising between the two approaches is fine for experienced folk like you and me, but not for a newbie.
 

If you wish to propose that idea that nitrification and aquatic plants interfere with each other under normal conditions, all I would like is scientific and not anecdotal evidence of this. What is the biology and chemistry that causes it. What I see on the plant sites is they say plant up the tank heavily with stem plants, wait about 2-4 weeks and add fish slowly. There is little difference between this and a fish in cycle in terms of time. And it is useless advice for those who have no desire to have heavily planted tanks but want some level of live plants.

I have explained the biology and a bit of the chemistry above, so hopefully this will help!
 

So he is saying that, without any ammonia addition to a new planted tank, the addition of co2 will amplify algae growth. Interesting......

I would have thought that to be obvious rather than interesting? Algae is just a simple plant so obviously adding CO2 will increase growth.
 
I'm think you may be taking that quote out of context? The Barr Report site is down for me atm so I cant read the thread to see why you think that quote is relevant.

 

[TwoTankAmin]

I think this discussion, for your sake, needs to back up to the nitrogen cycle itself. It seems to me you do not understand this process. It will take me a while to put together a proper post on this, which I will do. Bu I will say this much. The part of the greater nitrogen cycle that we see in tanks is often focussed on only the autotrophic bacteria. Fish keepers coopted the term cycling from the much bigger and more complex process of the global nitrogen cycle. I have only been in this hobby nor for just over 13 years. But when I began the number of fish keepers who were using live plants was a lot smaller than it is today. Before then that number was even smaller. The result is for most folks in the hobby, they paid no attention to the role of plants in the nitrogen cycle. There was little need to. However, plants are a part of that cycle.
 
Nitrogen is essential for all life. Most life forms are unable to use nitrogen directly, so it must be fixed in a form which can be used. The first step in the cycle is ammonification. Nitrogen becomes part of ammonia (NH3) which can then be processed into other forms that can be used. But most life can not use NH3, it is toxic. So the next step is to convert the NH3 into things that can be used.
 
Here is a paper from Cornell University entitled "Nitrogen: All Forms Are Not Equal"
 

Nitrogen form
Plants have the ability to take up several chemical forms of nitrogen. The most common are: ammonium (NH4+), which has a positive charge; nitrate (NO3-), which has a negative charge; and urea, ((NH2)2CO), which has no charge. Many commercial fertilizer mixes contain a combination of all three nitrogen forms............
pH effect
Plants take up ammonium and other positively charged cations by releasing one hydrogen ion (H+) into the medium solution for each ammonium ion absorbed. Over time, ammoniacal nitrogen uptake increases hydrogen ion concentration thereby lowering the growing medium pH.

The uptake of negatively charged anions such as nitrate is most often accomplished by releasing hydroxide ions (OH-). In the medium solution, hydroxide and hydrogen ions combine to form water (H2O). Over time the reaction of hydroxide and hydrogen ions decreases hydrogen ion concentration and increases the medium pH.

Under some circumstances plants absorb a nitrate anion by simultaneously absorbing hydrogen ions or releasing bicarbonate. Like hydroxide ions, bicarbonate combines with hydrogen ions and thus raises the medium pH. The net effect of using a nitrate-based fertilizer is to increase the overall medium pH.
 
Ammonium toxicity
Often nitrogen is applied at concentrations greater than plants can readily absorb. Plants can take up and store additional nitrogen to use later if nitrogen becomes limiting. Nitrate can be safely stored by plants; but when plants take up and store too much ammonium, cell damage can occur. Luckily, under normal conditions of warm temperatures and a well aerated medium, urea and ammonium are converted to nitrate by nitrifying bacteria so there is little worry about excess ammonium in the medium.

from http/www.greenhouse.cornell.edu/crops/factsheets/nitrogen_form.pdf
 
Wow- are they saying the plants and the bacteria are working in concert there not in competition?
 
Plants use ionized forms of fixed nitrogen- NH3 has no charge, NH4+ has a positive charge. NO3- (nitrate) has a negative charge. Plants use the  NH4 and the NO3, not the NH3. They use the urea, not NH3. What is more interesting is that certain plants, notabaly the legumes, develop a symbiotic relationship with a bacteria which colonizes parts of the the roots and this bacteria is able to take in Nitrogen directly as a gas and convert it to NH3 which is then further converted to a form the plants can consume.
 

What happens during nodulation?

Nodules are the tissue (small swellings) on the root system of legumes that house the rhizobia. Signals in the form of organic molecules, called flavonoids, from the plant communicate with the rhizobia. In most legumes, root hairs near the growing root tip curl as rhizobia attach to the tip and an infection thread forms within the hair to allow bacterial entry. The plant produces a new meristematic region where rapid growth occurs to house the rhizobia and to provide them water and nutrients. The rhizobia, in return, use part of the nutrients provided to produce ammonia (NH3) from N2. The NH3 is then converted into an organic compound for transport and use by the plant.

from http/www.public.iastate.edu/~teloynac/354n2fix.pdf
 
The above again illustrates that the plants are not using NH3 directly. They need their nitrogen in a different form to be able to use it.
 
Aquatic plants are not hugely different than those which grow in soil or marshes. They all photosynthesize, they need nitrogen, co2 and other things in common. While the proportions and specifics vary, the basic processes are the same. The biggest difference is in how the nutrients are delivered. Aquatic plants will leaf feed more than terrestrial plants. But this doesn't mean that aquatic plants are not root feeders.
 
When you get Tom Barr's site working again poke around and you will see Tom suggests one is best served using a combination of fertilizers in both the water column and the substrate- he says why do only one when both work well and together they work best. Many plants which could feed just fine solely from their roots can also feed from their leaves. And when enough nutrients are present in the water will do so. However, when one researches more in depth one will also discover that various plants have differing affinities for different things and these things may be best obtained from the roots or the leaves specifically depending on the plant and the location of the nutrients in their ecosystem.
 
I find this interesting in light of short exchange I had with Tom back in 2001 or 02 regarding substrate ferts. I seem to recall back then he was a bigger proponent of water column ferts which is different from what I see these days from him. The specific exchange was on another forum and was basically about the use of Jobe's Spikes as a substrate fertilizer. I have used them for over a dozen years now. However, Tom was less of a fan of them because of their one drawback. If one is an active replanter/rescaper, Jobe's spike allowed to be dug up and allowed to dissolve in the water table will cause awful algae blooms while in the gravel they release gradually. Since many folks who are heavy planters are also rescapers and transplanters, Jobes are not ideal for them.
 
Despite that fact that I gardened in the dirt for about 20 years before getting into tanks and then into planted tanks, I never paid a huge amount of attention to the biology and chemistry involved. I am much better versed in the dynamics of the autotrophic nitrifying bacteria involved with that part of the nitrogen cycle than I am with plants biology and chemistry. I came to live plants in my tanks for reasons other than most plant mavens. I got into them when I learned I could stock more heavily with live plants. I could do this because plants were bio-filters, because plants provided good cover for fish who needed to hide from others and for fry and because plants help oxygenate the water. And that was all I needed to know to get me started with live plants.

 

[three-fingers]

I think this discussion, for your sake, needs to back up to the nitrogen cycle itself. It seems to me you do not understand this process

Nope. I understand the nitrogen cycle. What you don't seem to understand are basic chemical processes (ammonia absorption in plants) and biological processes (the competitive exclusion principle).  I have already explained the competitive exclusion principle to you several times, however you seem to just be ignoring this info, not even commenting on my points. You cannot just redefine "competition" to suit your needs unfortunately.  I will state once again - filter bacteria and plants are in competition for the limited supply of nitrogen.  You cannot change this fact, it doesn't matter what your opinion is - its basic biology taught in schools.  The idea of them working in "concert" is pure illusion on your part. They are both providing a function that contributes towards for our needs (clean aquarium water), sure, but they are doing it totally independently without any other known biological interaction other than competition.  If the plants take more ammonia, there's less bacterial growth and vice versa.   Plants and bacteria are both part of the cycle, yes, competing with each other...
 

Wow- are they saying the plants and the bacteria are working in concert there not in competition?
 
Plants use ionized forms of fixed nitrogen- NH3 has no charge, NH4+ has a positive charge. NO3- (nitrate) has a negative charge. Plants use the  NH4 and the NO3, not the NH3. They use the urea, not NH3. What is more interesting is that certain plants, notabaly the legumes, develop a symbiotic relationship with a bacteria which colonizes parts of the the roots and this bacteria is able to take in Nitrogen directly as a gas and convert it to NH3 which is then further converted to a form the plants can consume.

Yes, but they are talking about a completely different scenario.  This scenario has no light, no algae and lots of aeration around terrestrial plant roots.  Please think about the relevance of a study before you link to it.
 
NH3 has no charge, but that has no bearing on our discussion, because it gets into the plants cells via osmosis.  That fact, along with what I have already stated about plants using urea, renders your whole line of thought of "there will be NH3 present and there will be bacteria taking advantage of that" as baseless.  There won't necessarily be NH3 present. Accepting that aquatic plants can use all of those forms of nitrogen discussed, one should easily see how this could negatively affect the growth of bacteria in a fishless-cycling aquarium. 
 

from http/www.public.ia...ac/354n2fix.pdf
 
The above again illustrates that the plants are not using NH3 directly. They need their nitrogen in a different form to be able to use it.
 
Aquatic plants are not hugely different than those which grow in soil or marshes. They all photosynthesize, they need nitrogen, co2 and other things in common. While the proportions and specifics vary, the basic processes are the same. The biggest difference is in how the nutrients are delivered. Aquatic plants will leaf feed more than terrestrial plants. But this doesn't mean that aquatic plants are not root feeders.

 
 Once again, you have referenced to a totally irrelevant paper.  I have already explained why papers related to terrestrial plants, growing with their roots in the dark in an aerobic environment are not relevant to this discussion. I asked you why you thought the last papers you linked to on this topic were relevant, and you have just responded by posting more papers basically about the same thing?

 
That excerpt is an especially bad choice as its refers to legumes - very well known for their symbiotic relationships with bacteria in the soil.  In fact, since you have been gardening in the dirt for 20 years, you should be familiar with people "companion planting" things like beans and corn together, as the bean plants root bacteria will help supply nitrogen to the corn too.
 
Aquatic plants have to deal with a whole host of problems that terrestrial plants don't! As I have listed before, fluctuating nutrient values, pH, CO2, oxygen, light and of course our biggest nemesis in the planted tank world - algae.  None of the studies you have provided account for these factors.
 
I have never once implied that aquatic plants aren't root feeders, so I don't know what your trying to get at here.  Of course they can feed from the roots too, however, as I have pointed out already, the root environment for aquatic plants is generally anaerobic, and those studies you linked to only deal with the aerobic root environments that nitrogen fixing bacteria and fungi love.  So aquatic plants being able to feed from the roots is a moot point. 
 

I seem to recall back then he was a bigger proponent of water column ferts which is different from what I see these days from him.

 He still is a bigger proponent of water column dosing - nothings changed except from this line of thought has evolved into dosing methods such as EI. The idea being that aquatic plants can easily get 100% of their nutrition from the water column if no nutrients are limiting. With EI dosing, substrate fertilisers are redundant if you are dosing correctly, however he would still say root fertilisation is useful just as a fall-back in case you miss some dosing or there's some other nutrient supply issue. Substrate fertilisers can also be great on their own in low-tech tanks.
 

I came to live plants in my tanks for reasons other than most plant mavens. I got into them when I learned I could stock more heavily with live plants. I could do this because plants were bio-filters, because plants provided good cover for fish who needed to hide from others and for fry and because plants help oxygenate the water. And that was all I needed to know to get me started with live plants.

Same here

. At first I had little interest in growing plants, I just chucked some in the aquarium for fish food/cover.  My priorities were on the fish side of things to begin with. Once I had witnessed their water purification capabilities first hand, and how this benefited the fish however, I had to know more!  Now I enjoy gardening as a hobby too, and have learnt enough from playing around with hydroponics and high-tech planted tanks that its enhanced my understanding of general fishkeeping topics, especially highlighting all the variables and complications involved with cycling.
 
Hopefully now that some things have been cleared up about ammonia uptake and root bacteria, you can appreciate how these factors might complicate a fishless cycle. 

 

[TwoTankAmin]

OK let me explain it this way. Bacteria and plants do not compete for ammonia (nitrogen). Competing implies there is some sort of equality involved where either side can "win." But plants can uptake ammonium faster than the bacteria can. So I suppose if you want to consider a race between a healthy 20 year old and a healthy 7 year old as competition, then in those terms you are partially correct. But what if the 20 year old is asleep when the race is started?
 
So lets consider the entire process in terms of photoperiod. The bacteria do not sleep. They work 24/7. The same is not true for plants. During dark hours they are not taking in co2 and putting out O. They are not photosynthesising but rather are using the energy they created during the day and stored to get through the night. So the plants are not uptaking ammonia or nitrate during dark hours. But the fish do not stop creating ammonia just because it it dark. Fish may create less ammonia when they are less active at night, but as long as they are respiring, they are passing ammonia into the water. Bacteria do not care if there is light or not to uptake ammonia etc.. Plants need light to photosynthesize. Moreover, the creation of ammonia from the decay of organic matter is 24/7 as far as I am aware.
 
So can you explain what happens to all the ammonia created in a well planted tank in the dark? And let me make it even harder to answer. Explain it in a tank with some portion of nocturnal fish which means they will create more ammonia than a tank where most of the fish are inactive during dark hours?
 
In order for higher animals to get the nitrogen they need, they get it from eating. Nitrogen gets into our systems from plants as the first stage. Animals eat plants which provides them with their nitrogen needs. If one animal eats another, it derives fixed nitrogen from the consumed animal. Some animals are omnivores and eat both.
 
The cycle is simple: Nitrogen is converted (fixed) by bacteria into NH3. NH3 becomes a mix of ammonia and ammonium in water. Plants can uptake ammonium (and nitrate) to get the nitrogen they need. But the nitrate comes from the bacteria which have consumed the ammonia/nitrite to create that nitrate. In the absence of man who puts or "pollutes" the environment with fertilizer which usually is a combination of ammonium, nitrate and urea, the presence of nitrate mostly would come from bacteria processing ammonia.
 
Once the initial fixing has created the ammonia/ammonium plants in sufficient quantities can consume and use most of it, but not at night. For this bacteria must do the work. So the reality of this is that there can be tanks where 100% of the ammonia is processed by bacteria. However, no matter how many plants one puts into a tank, they can not take up all the ammonia being produced due to photoperiods. There is always some amount of bacteria in all planted tanks.
 
Now you choose to call what is going on as competition. But it is not so much competition as is is the plants being more efficient "nitrogen" consumers than bacteria. But the plants can not consume it all, as I have shown, so there must be bacteria in any tank. We as hobbyists may never see that ammonia with our test kits. Put in sufficient plants (which also bring in bacteria) and a tank appears to be cycled silently.
 
What should make all this make even more sense is the fact that the plant gurus who state plant well, lets the plants settle in and then add fish gradually are insuring there will never be an ammonia reading. The only safe way i know to fully stock a brand new planted tank right away is to insure there is also sufficient bacteria present to handle the dark hour productions of ammonia.
 
three, I am eager to see your response to all this. From my point of view, in a well planted tank there is still a nitrogen cycle at work and there is still bacteria needed and present, However, the balance between plants and bacteria will depend on how many plants one has in the tank. To my mind this is not different than a pair of identical 20 gallon unplanted tanks. Put twice the number of fish in one as in the other and that heavier stocked tank will contain more bacteria than the lighter stocked. This is merely because there is less ammonia available. This is not much different than a tank with plants which leaves less ammonia that needs to be handled by bacteria. There is not an absence of bacteria, there is just less need for it. The plants and the bacteria work together to insure all the ammonia is handled. One is working more during the day and the other at night.
 
And the main difference between aquatic plants and terrestrial plants is the former can usually feed from their roots and their leaves while land plants tend to rely primarily on their roots. But there are many aquatic plants which do rely exclusively on root feeding. They are the ones in more acid water devoid of most nutrients. They either feed via their roots or the can not survive. But terrestrial plants can also take things in via their leaves. For example, I have fed iron to trees via their leaves. But the basic processes of plant biology are fairly similar in both types. And for that reason many comparisons between land and aquatic plants are entirely appropriate to cite. Perhaps you can explain to me what the difference is between and aquatic plant taking up ammonium/nitrate vs a land plant. Do they need different forms of ammonium, do they photosynthesize differently? Do the not need similar trace elements?

 

[three-fingers]

OK let me explain it this way. Bacteria and plants do not compete for ammonia (nitrogen). Competing implies there is some sort of equality involved where either side can "win."

No. That's not even the definition of "competition" outside the context of biology. Look here, or even here. But this is what we're talking about here. There is no equality implied in competition whatsoever. Please stop trying to twist the definition to suit your argument.
 

So lets consider the entire process in terms of photoperiod. The bacteria do not sleep. They work 24/7. The same is not true for plants. During dark hours they are not taking in co2 and putting out O. They are not photosynthesising but rather are using the energy they created during the day and stored to get through the night. So the plants are not uptaking ammonia or nitrate during dark hours. But the fish do not stop creating ammonia just because it it dark. Fish may create less ammonia when they are less active at night, but as long as they are respiring, they are passing ammonia into the water. Bacteria do not care if there is light or not to uptake ammonia etc.. Plants need light to photosynthesize. Moreover, the creation of ammonia from the decay of organic matter is 24/7 as far as I am aware.

Your assumption that plants aren't using nutrients at night is simply incorrect, so it follows that the rest of your argument based on this assumption is also incorrect.  They use more nutrients during the day time when they are photosynthesising, of course, but they are still respiring and otherwise living during at night time, they still need nutrients to maintain cells, fight disease, etc..  Even if you were correct about active uptake at night, your once again forgetting about osmosis, which happens in the light or dark.  
 
At this stage in the discussion I've already summarised all of my points above repeatedly, and have quoted and refuted all of your points, as well as directly answering all of your questions.  Until you start answering some of my questions and you can refute or at least show some acknowledgement of the points I have made, this discussion unfortunately cannot progress any further.
 
Suffice to say, I'm confident that anyone reading this will see that I've made a structured and coherent argument for the case of not fishless cycling high-tech planted tanks, and removing plants from tanks that are being fishless cycled until after the cycling process.  Simple suggestions with sound reasoning based on the competitive exclusion principle.
 
The links I've provided above posts are good resources for anyone seeking more information. If anyone else has any questions, feel free to PM me, or PM me a link to a thread!
 
Happy fishkeeping

.

 

[daizeUK]

I'm not sure what to think, to be honest. I can see arguments from both sides but there are still things I'm unclear on.
 

Light + ammonia = algae

This makes a lot of sense and seems the biggest reason to me why cycling with plants might be a bad idea.
 

Plant the tank, then cycle it. Because plants consume ammonia, They reduce the amount of bacteria a tank might need to handle its full stocking. This mean that given two identical tanks except one has live plants and the other does not, it will require more bacteria in the tank without plants to handle any given bio-load. This tank will require 5-6 weeks to cycle. But the planted version will be cycled in much less time.

I can see sense in the argument that there isn't much point building up a full healthy colony of bacteria if you are going to add plants later that will do the same job, however I don't see this as a crucial deciding factor (unless you are really desperate to cycle as quickly as possible). In my mind, who cares if it takes a bit longer or if half the bacteria end up dying as long as the ammonia is all getting processed? Either way the fish won't get hurt so it doesn't matter.
 

Not necessarily, because as I explained above, too many different factors affect plant health, which in turn affects ammonia uptake. The first day the plants may be up taking 50% of the of ammonia, the 2nd day of the cycle maybe 25% and next day it could be 75%. Unless you are doing all you can to ensure the plants are totally healthy, theres no way to estimate how much the plants are taking up compared to the bacteria. It would be total guesswork (especially for a beginner) how much bacteria you have at the "end" of your cycle, and this could obviously be disastrous for a beginner.

My understanding of nitrifying bacteria is that they will not be affected by daily fluctuations in ammonia concentration. If they were then this would be a known problem in almost any planted tank. During the fishless cycle I imagine the bacteria will establish a colony according to the average ammonia available over a period of time and by the end of the cycle this population should be well enough established to adapt quickly to any changes. I can't visualise a scenario where there might be disastrous results, can you explain?
 

Not all plants are remotely equal in their ability to tolerate/uptake ammonia. There are HUGE documented variances even among related species of common aquarium plants. For example in a study, Egeria canadensis was shown to have a 20% reduction of photosynthesis when exposed to 3.2ppm ammonia, while Egeria nuttallii showed no observable change even at 9ppm. For some plants, 0.5ppm could potentially stunt growth just enough to let algae take over, spelling eventual doom for the plant. Some can tolerate higher levels, it just depends on their evolutionary history. And remember its not just certain ppm at which ammonia suddenly becomes toxic - lower levels have a chronic effect on plants just like fish.

This was very interesting and I agree that sensitivity of plants to ammonia could be an important factor. Several fishless-cycling products on the market carry a warning not to use with plants for this reason.
 

 

But lets touch on one part of this discussion that has been omitted completely. It as stated its too complicated for a newbies to grasp what I am saying and to do what I suggest. Yet there is no problem regarding acomplete newbie to take their first step into live plants at the most sophisticated and complex level possible with no experience in live plantsat all. To me this is akin to telling a newbie that the first fish they can keep are wild altum angels. I liken getting into live plants that way as one's learning to drive for the first time in an Indy 500 race car. Imo, learning how porperly to manage a high light, co2 added regularly fertilized tank is not exactly easy.

That's just another bad analogy. High-tech tanks and following modern advice on planted tanks is not "the most sophisticated and complex level" at all. It may seem that way to you, because you don't currently don't understand the behind the biological processes, but the modern equipment and advice actually make it much easier to set-up and maintain a planted tank. Compromising between the two approaches is fine for experienced folk like you and me, but not for a newbie.
 

I have to agree with TwoTankAmin on this. Performing a 'silent cycle' is a huge ask for a beginner or even an intermediate-level fishkeeper.

I'll use myself as an example. I'm relatively new to the fishkeeping world, having started about a year ago and since then I've been steadily learning that plants are by far the most complicated (and expensive!) part of the hobby. I'm now at a level of knowledge where I am EI dosing with home-mixed dry ferts to my own recipe and experimenting with yeast CO2 reactors.

With my latest tank (the 120L in my sig) I decided to plant first and then conduct a fishless cycle with ammonia as TTA would recommend (also using mature media as a starter). This took three weeks of fishless cycling in a planted tank before the tank was successfully processing 3ppm of ammonia and the resulting nitrite.

Three weeks! - well, admittedly I wasn't trying to silent cycle or following guidelines for silent cycling, but that's an indication of just how far away I was from a silent cycle with this planted tank. I was nowhere near. Admittedly there's a lot of slow-growing, low-light tolerant plants rather than fast growing stems, but these plants are perhaps typical of what a beginner might choose to use. This indicates to me that if I'd assumed I could 'silently cycle' this tank and tried to add fish after the plants, I'd have ended up with some very miserable fish. Perhaps it's not the best example but I do think that it's a very tall order to expect complete beginners to conduct a silent cycle successfully - they'll just end up with a fish-in cycle.

I probably should have done the fishless cycle first and then planted afterwards as you suggest - I might have saved myself some algae! But the fish would have to be added immediately after the cycle completed which would leave me very little time to arrange hardscape and finish planting, and no time at all for the plants to establish before adding fish. What would you have done in my case, three-fingers?