Silent Cycle - will the bacteria establish themselves as well?

[Micko50]

Hey everyone,

I just have a question i'm hoping you can answer.

I am a newbie and have just started my first tank set up. I got the Juwel Rio 180L with their standard filter media and pump set up.

Added API Quickstart and planned to do a fish-less cycle. Went to my local aquarium to get some Ammonia and some live plants and I was recommended to get some fish straight away. Ended up getting 10 neon tetras and 3 large java ferns. Added 2 more doses of quickstart in the first week. Using the APL master test kit, I tested every second day and got 0 ammonia, 0 nitrites, 0 nitrates. No dramas.

Week 2: Had a large Algae bloom!; still 0 ammonia, 0 nitrites, 0 nitrates. Added 2 Hornwort plants and an Anubais on driftwood. Added 3 Otos and 2 pleccos. Did a 15% water change. Used API water conditioner.

Week 3 and 4: Ammonia was max 0.25ppm, still 0 nitrates and 0 nitrites. Did a 35% water change on Saturday. Ammonia levels hover between 0 - 0.25ppm. 0 nitrites or 0 nitrates still.

Tank parameters: pH 7.6 - 8.2. Temp 24 - 26 degrees Celsius, Hardness of our water is 71ppm (4 dH).

Had zero fish losses, Hornwort plants are turning pink/brown at the top. Algae under relative control. Fish seem happy and show no signs of stress. Just added 9 Guppies yesterday.

I seem to have inadvertently done a silent cycle, the plants seem to me to take all the Ammonia and Nirites and leave very little for the bacteria to feed on. I have been expecting an ammonia spike, followed by nitrates and then nitrites, but that hasn't happened.

MY QUESTION: - will the bacteria establish themselves once I continue to gradually introduce more fish? Will I get an ammonia spike, then go through a regular cycling process?

Ideally I don't want to rely on plants alone for cycling, would like the bacteria to do some work too.

Any help or advice would be greatly appreciated.

 

[mbsqw1d]

it doesn't sound like you have anywhere near enough plants to completely take over a nitrification process - lots of fast growing stem plants are usually used in planted cycles. Anubias for example are a slow growing plant. I'd hang on a little while before adding more fish as plecos are messy fish and will be outputting a lot of ammonia. You may have difficulty with the Otos as they really do not like ammonia or changes in the water parameters. Keep up with the water changes and testing for nitrogen

Unfortunately the guppys prefer hard water and your water is rather soft, this will ultimately shorten their lifespan.

 

[seangee]

Keep testing daily. When doing a silent cycle you need to add fish slowly. Most people wait 2 weeks to ensure everything is ok before adding a few more. @mbsqw1d is right on both counts. I recently did a silent cycle and added around 30 plants to the substrate, and mine is only an 85l tank. These were all fast growing plants. I also completely covered the surface with frogbit.

The comment on guppies is also valid. There is no point in trying to increase the hardness because that will be detrimental to all of your other fish, which need soft water. Worth keeping in mind for future stocking options and concentrate on the soft water fish. Next addition should be more neon tetras as these are much better in large groups - but wait to verify that the tank can cope with the current bio-load before adding more fish.

 

[Micko50]

Thanks for your response - the plants are the only reason I could come up with why the cycle hasn't started. I'll continue to monitor the levels and be patient - it's only been 4 weeks so far.

May have to harden the water up a bit - hopefully the guppy's can acclimatise.

 

[Kevstar]

Your question is something I have wondered about regarding the silent cycle. If the plants are so efficient at removing ammonia then is the filter ever truly cycled.

Lets assume that the plants take up 80% of the ammonia being produced by the live stock then that still leaves 20% for the beneficial bacteria to feed on and create an establish a colony in the filter media, if this is the case then the water is unsafe for livestock and the silent cycle isn't working.

Now lets assume that the plants are consuming 100% of the ammonia (also assuming that multicellular plants are more effective than single celled organisms like the bacteria) then the bacteria would be starved of their food source and would not be able to grow and create what we call the nitrogen cycle.

So, if the latter is true, then theoretically the filter would not cycle and you would be completely relying on the plants to create a safe environment for livestock. So if (for whatever reason) the plants slow down their growth rate, or even worse start to die off then the filter would have to start at the beginning stages of the nitrogen cycle and would not be able to deal with the increased ammonia.

This is slightly hypothetical thinking of course from my basic understanding of water chemistry and the nitrogen cycle.

Anyone with greater experience and understanding, please feel free to correct my uneducated understanding of this process

 

[Micko50]

Keep testing daily. When doing a silent cycle you need to add fish slowly. Most people wait 2 weeks to ensure everything is ok before adding a few more. @mbsqw1d is right on both counts. I recently did a silent cycle and added around 30 plants to the substrate, and mine is only an 85l tank. These were all fast growing plants. I also completely covered the surface with frogbit.

The comment on guppies is also valid. There is no point in trying to increase the hardness because that will be detrimental to all of your other fish, which need soft water. Worth keeping in mind for future stocking options and concentrate on the soft water fish. Next addition should be more neon tetras as these are much better in large groups - but wait to verify that the tank can cope with the current bio-load before adding more fish.

Thanks for your advice - will definitely keep testing and will hold off on more fish for now.

With the guppies - lesson learnt. Will aim to stock soft water species from now on.

 

[mbsqw1d]

Plants are more efficient at consuming the ammonia than the BB (i have read), so yes if for some reason you remove the plants or for some strange reason they all die.. then yes, the BB would have some catching up to do. Removal of the plants would be the bigger risk opposed to the slower rate of plants dying off (although this itself would create ammonia from dead plant matter)

Worth saying that using plants to remove ammonia is safer for the fish than using BB. Plants do not turn the ammonia into another fairly dangerous substance (nitrate) like BB does, which you then need to remove with water changes, instead plants simply uses it (ammonia) for food > growth.

 

[Micko50]

I am happy that the plants are taking the ammonia and I'm not seeing any nitrites or nitrates. Ideally would like the dual removal system of plants and an established BB colony. But if the plants work, then I will keep adding plants as I go until my ecosystem is well established. Perhaps the BB will establish if there is enough left over ammonia around. Will add some more bacteria and see if it colonises. Thanks for your responses

 

[mbsqw1d]

There will definitely be some nitrifying bacteria growing even in planted tanks, at this stage it just seems too low to be measured by your kit. Do you measure any nitrate in the water direct from your tap, before adding any water conditioner (ie Seachem Prime) ?

 

[Micko50]

There will definitely be some nitrifying bacteria growing even in planted tanks, at this stage it just seems too low to be measured by your kit. Do you measure any nitrate in the water direct from your tap, before adding any water conditioner (ie Seachem Prime) ?

I haven't yet but I will tomorrow when I do a tank water test.

 

[seangee]

Your question is something I have wondered about regarding the silent cycle. If the plants are so efficient at removing ammonia then is the filter ever truly cycled.

Lets assume that the plants take up 80% of the ammonia being produced by the live stock then that still leaves 20% for the beneficial bacteria to feed on and create an establish a colony in the filter media, if this is the case then the water is unsafe for livestock and the silent cycle isn't working.

Now lets assume that the plants are consuming 100% of the ammonia (also assuming that multicellular plants are more effective than single celled organisms like the bacteria) then the bacteria would be starved of their food source and would not be able to grow and create what we call the nitrogen cycle.

So, if the latter is true, then theoretically the filter would not cycle and you would be completely relying on the plants to create a safe environment for livestock. So if (for whatever reason) the plants slow down their growth rate, or even worse start to die off then the filter would have to start at the beginning stages of the nitrogen cycle and would not be able to deal with the increased ammonia.

This is slightly hypothetical thinking of course from my basic understanding of water chemistry and the nitrogen cycle.

Anyone with greater experience and understanding, please feel free to correct my uneducated understanding of this process

Your assumptions are pretty much correct. The important factor is that the system as a whole is capable of dealing with all the ammonia produced within the system. In my case my pH is very low. The bacteria is actually incapable of surviving in my tanks so my "filter" will never be cycled - but the system as a whole is capable of dealing with all the ammonia produced. Obviously this has some advantages, e.g. last week I replaced a filter in my newest tank. I just took out the old one and put in a new one without worrying about seeding it - but of course I have still been testing for ammonia daily.

Conversely there are also disadvantages. I have no backup plan if all my plants die overnight.

The silent cycle gives you the best of both worlds. The hard part of the cycle is getting the initial colony of bacteria established. Once established it is capable of doubling every day (or even faster). Technically there are 2 types of bacteria but using one is easier as an example . So in your 80/20 scenario if the plants die the filter is ready to pick up the load very quickly. It may take a day or to for the bacteria to ramp up but this is not a disaster. Similarly if the filter breaks down the plants are doing 80% of the work anyway so it is not a disaster - and lots of the bacteria exists outside of the filter on the substrate and other surfaces so you should never see an ammonia spike.

 

[Kevstar]

So to fully cycle an aquarium we add ammonia up to 4 ppm(to fully stock it) but without an initial cycling period and adding ammonia we assume that a fully stocked aquarium still produces 4 ppm, lets say that with a silent cycle the plants are taking up 3 ppm and the filter would eventually grow to consume 1 ppm. To my way of thinking this still leaves a considerably unsafe period for livestock to be safe.

But unless I'm reading incorrectly, due to the fact that your pH is on the low side we know that the bacteria never grows to consume ammonia. So in this case the plants are consuming all of the ammonia and my initial assumption is that the filter never cycles, so in all heavily planted aquariums this would be considered the norm.

Now, talking from experience with a heavily planted aquarium, I have added an uncycled filter for a duration to cycle it. They have always cycled and when adding them to a brand new aquarium (not heavily planted) the water parameters have shown a cycled filter is present (0, 0, 10 after a period of adding livestock). so this proves that their must be a certain amount of ammonia present in a heavily planted aquarium to have cycled the filter?

Just thinking out loud here

 

[seangee]

Correct. The important part of a silent cycle is that you can't fully stock the tank on day 1. Hence the recommendation to add a few fish initially and then wait a few weeks (confirming that you have no ammonia or nitrites) before adding more fish. This allows the bacteria to build up gradually in the background (i.e. silently). Since all the water passes through the filter regularly it is inevitable that some ammonia goes in with it even if the plants can deal with 100% and the filter will eventually cycle.

 

[Kevstar]

Thanks, a silent cycle is a new way of doing things for me as I've always cycled my aquariums to 4 ppm or used an instant cycle, so queries were inevitable, how very interesting, thanks again for confirming I was on the right track.

 

[Retired Viking]

I have done silent cycles on all my tanks and I am very happy with the results. Balance is the key word. Keeping balance between what your fish produce in waste and what the plants can absorb. You also have an added advantage in that the fish produce CO2 for the plants and the plants produce oxygen for the fish and improve water quality.