Confused by readings

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Frogbit is a floating plant which will take up ammonia quite quickly, and won't turn it into nitrite. Mosses are slow growing and won't take up very much ammonia compared to frogbit. Depending on how much frogbit you have, there may be enough to use all the ammonia made by future fish - but it would need more than one or two plants.

Slate is an inert rock, which will not affect the water chemistry. But it can be sharp at broken edges so make sure you smooth off any sharp bits.


Having a reasonable KH during cycling is important for 2 reasons.
Firstly, as stated earlier, it stabilises the pH. If there is not much KH, it gets used up during cycling and the pH crashes. The bacteria do not grow well at very low pH.
Secondly, the bacteria need inorganic carbonate to multiply (as stated in the fishless cycling method on here). As KH, ie carbonate, is used up there is none left for the bacteria.

I see that scotty lives in Scotland and most of Scotland has very soft water with low KH. You should be able to find your general hardness GH on your water company's website to confirm that you do have soft water but unfortunately very few UK companies give KH (and where they do give it, they call it alkalinity rather than KH)
I would definitely do a big water change to replenish the KH the cycle has used up.
 
Frogbit is a floating plant which will take up ammonia quite quickly, and won't turn it into nitrite. Mosses are slow growing and won't take up very much ammonia compared to frogbit. Depending on how much frogbit you have, there may be enough to use all the ammonia made by future fish - but it would need more than one or two plants.

Slate is an inert rock, which will not affect the water chemistry. But it can be sharp at broken edges so make sure you smooth off any sharp bits.


Having a reasonable KH during cycling is important for 2 reasons.
Firstly, as stated earlier, it stabilises the pH. If there is not much KH, it gets used up during cycling and the pH crashes. The bacteria do not grow well at very low pH.
Secondly, the bacteria need inorganic carbonate to multiply (as stated in the fishless cycling method on here). As KH, ie carbonate, is used up there is none left for the bacteria.

I see that scotty lives in Scotland and most of Scotland has very soft water with low KH. You should be able to find your general hardness GH on your water company's website to confirm that you do have soft water but unfortunately very few UK companies give KH (and where they do give it, they call it alkalinity rather than KH)
I would definitely do a big water change to replenish the KH the cycle has used up.
I've always been told to keep plants out during cycling because it can cause erratic readings.
 
Plants take up ammonia as fertiliser but they don't turn it into nitrite, which means no nitrate either. So, yes, plants can cause erratic readings.

The other problem is that a lot of plants cannot tolerate a lot of ammonia in the water. With a tankful of fish, ammonia is produced in tiny amounts throughout the day and the plants take it up as soon as it appears. Fishless cycling adds the same amount of ammonia all at once so most of it remains in the water for hours till the plants can remove it, and this can kill plants.
Cycling should really be done in one of two ways - no live plants, and add ammonia; or lots of live plants and add fish a few at a time, making sure by testing that the plants are taking up all the ammonia made by the fish, uneaten food, fish waste etc so that no ammonia is present to harm the fish or to be turned into nitrite.

When there are only a few plants, as in this case, I would remove the plants to a bucket for the duration of the cycle and add ammonia as per the instructions on here, or get a lot more plants and don't add ammonia.
 
I would suggest differently. Moving plants can set them back, even kill them, if conditions are substantially different, such as light, nutrients, water parameters (GH, pH, temp). If the plants seem healthy now, leave them in the tank. But do not add ammonia.

And while I am here, I will comment on some earlier advice that is not really accurate. Advice has been given to use ammonia to maintain the nitrifying bacteria that have been established, on the belief that if this is not done the bacteria will die off. This makes no sense. When plants are present, and admittedly subject to their rate of growth and numbers, they take up ammonia/ammonium as their preferred source of nitrogen. But they do it faster than the nitrifying bacteria, according to scientific studies. So what is going to happen to your established colonies of bacteria then? If you maintain that not adding ammonia now will cause the bacteria to die off, it follows that they will die off later due to the plants. Which is why I say, do not add further ammonia, you are risking the plants.

Second point is that nitrifying bacteria will not die off if ammonia decreases. The bacteria will go into a sort of suspended state like an hibernation. This citation is from an article in PFK:

AOBs die in absence of ammonia – nope.

Another ‘folk wisdom’ follows that without a continuous food source, AOBs will soon starve, die, and it’s game over. A scout around various forums reveals that the usual time suggested by well-wishers (myself included) hovers at about eight hours before the Nitrosomonas will turn their tiny starved toes up.

Again, the research forces a rethink. It’s noted that Nitrosomans europa can be starved for weeks or months, and then when placed in ideal conditions (in this case experimental ones, admittedly) regain their abilities to oxidise ammonia within just a few minutes. Older studies put forward a more lingering timescale before reactivity, over 150 hours before oxidising is properly resumed, but the fact remains that the AOBs are bouncing back from hardship.

But, and it is a but that can’t be ignored, there is more to this than may meet the eye. Although the recovery of single cells can be rapid, an entire population may take somewhat longer to emerge. And autotrophs are notoriously slow at ‘dividing and conquering’.

Different Nitrosomonas bacterial strains reactivated at different rates, and what seems to have some consistency is the longer the time in starvation, the longer the time for recovery.​

You can read the article here:
https://www.practicalfishkeeping.co...you-know-filter-bacteria-dream-on?rq=bacteria
And the scientific study here:
https://academic.oup.com/femsec/article/58/1/1/468326

The science is quite involved, and it makes clear that other factors like temperature and pH are involved.
 
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Would this apply to Christmas moss and frogbit? He says he has 5 different plants but names only those two, which I took to mean he had 5 plants in total, and there were all either frogbit or moss.
I suppose it could be 5 different unnamed plants, plus Christmas moss, plus frogbit?



Scotty - exactly how many plants do you have?
 
Would this apply to Christmas moss and frogbit? He says he has 5 different plants but names only those two, which I took to mean he had 5 plants in total, and there were all either frogbit or moss.
I suppose it could be 5 different unnamed plants, plus Christmas moss, plus frogbit?

Scotty - exactly how many plants do you have?

Good point (knowing the plant species and numbers), and one I raised earlier in this thread but it wasn't answered. Frogbit however is a fast growing plant, all floating plants are fast growing because they have the aerial advantage. Leaves at the surface will assimilate CO2 from the air, a process which for plants is about four times faster than those having to assimilate carbon from CO2 in the water. And light is also stronger at the surface obviously. So floating plants are rapid growers. Many have termed them "ammonia sinks" because of the amount of ammonia they can take up. There is still a limit, as ammonia is toxic to all life forms, even the ammonia oxidizing bacteria we are so wanting to cultivate. That is another issue, but all this ammonia being added can kill the nitrifying bacteria itself.
 
Thanks for the photo. My advice stands, do not add ammonia, but do add plant fertilizer. A comprehensive liquid will help, and substrate tabs (one next to each of the two sword plants) will greatly benefit these plants.
 
OP has fish ordered and they won’t be in until next week. Normally you are encouraged not to do water changes during a fishless cycle unless absolutely necessary. That’s why I suggested not doing a change yet. Crashes don’t happen as easily as people are led to believe. However, I don’t want to be responsible if a crash occurs. If it were my tank, I’d let it ride but you need to do what you feel is right. Byron, if ammonia is not added, what will feed the bacteria? Do plants produce something?
 
OP has fish ordered and they won’t be in until next week. Normally you are encouraged not to do water changes during a fishless cycle unless absolutely necessary. That’s why I suggested not doing a change yet. Crashes don’t happen as easily as people are led to believe. However, I don’t want to be responsible if a crash occurs. If it were my tank, I’d let it ride but you need to do what you feel is right. Byron, if ammonia is not added, what will feed the bacteria? Do plants produce something?

Nothing feeds the bacteria, it is not needed. The Nitrosomonas sp. AOB (ammonia oxidizing bacteria) will not die off in the absence of ammonia. What do you suppose it does in tanks with plants, when the plants use all the ammonia (or very nearly all) continually? And no, plants do not produce ammonia except if they die, as decomposition of organics produces ammonia.

A related example. I have a QT tank for new fish acquisitions. It is permanently running, with plants culled from the other tanks, including a thick layer of floating plants. This tank has run for months, well over a year sometimes, before I find new fish. I bring home 20, 30, 40 fish and they go into this tank. There is never any "cycle" as such, and ammonia and nitrite remain zero. Nitrates tend to run in the 0-5 ppm range. The plants take up all the ammonia those fish produce immediately. I expect there are AOB and NOB (ammonia and nitrite oxidizing bacteria) in the tank (it has a dual sponge filter which I rinse under the tap) maybe, but they are not being fed during the months there are no fish present, though I admit there are snails. But 40 or so fish suddenly introduced to this tank would overwhelm any bacteria but it is not an issue because of the plants.
 
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Hmmm, interesting. I was taught that you had to have a food source of ammonia. I believe you’re mistaken but I will see what I can find.
 
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Hmmm...here’s a post from Fishlore talking about the subject and Dr. Tim’s view on the subject. I found an article that does conflict with this and stated the bacteria can go dormant but all other articles dispute this. The consensus is that you do need the ammonia source. It can be from fish food, fish waste, decaying plant matter, etc. This is from a Fishlore member...”When I emailed Dr Tim and inquired about how often I should add ammonium chloride drops to my QTtank while it was empty so that the BB wouldn't die off, he said in order to keep them alive and reproducing to add it twice a week.”​
 
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Hmmm...here’s a post from Fishlore talking about the subject and Dr. Tim’s view on the subject. I found an article that does conflict with this and stated the bacteria can go dormant but all other articles dispute this. The consensus is that you do need the ammonia source. It can be from fish food, fish waste, decaying plant matter, etc. This is from a Fishlore member...”When I emailed Dr Tim and inquired about how often I should add ammonium chloride drops to my QTtank while it was empty so that the BB wouldn't die off, he said in order to keep them alive and reproducing to add it twice a week.”​

I am not the best person to be leading this discussion because my understanding is based upon my research and not as a biologist or microbiologist. TwoTankAmin is a member here who has delved into this much more deeply and could provide us with all sorts of references; he wrote the articles pinned at the top of the cycling forum, and these do recommend adding ammonia periodically. However...

I cited a paper in post #49 which determined that the AOB do not die off rapidly in the absence of ammonia; conditions factor in, as I said. But the evidence is very clear that depending upon these conditions, the ammonia can go into a sort of suspended state for weeks and even months. There is also the evidence in other studies that high ammonia levels can inhibit the NOB (nitrite oxidizing bacteria) which may explain why some people have issues with nitrite reduction during cycling; I would suspect the NOB are being inhibited if not killed by the ammonia. Even the AOB themselves can be killed by excessive ammonia.

But that is not really the point, when plants are present. Aquatic plants use ammonia/ammonium as their preferred source of nitrogen, over nitrite and nitrate. I have never cycled a fish take in my life, but I always have floating plants and lower plants in from day one, and then add the fish. If the plants were not taking up the ammonia, all my fish would never have lived past a day or two. In her book Ecology of the Planted Aquarium, Diana Walstad has dozens of citations from scientific studies on the topic.

Plants rapidly detoxify ammonia. As NH3 (toxic ammonia) enters the cell by simple diffusion across the membrane, it may combine with a hydrogen ion (H+) and convert to non-toxic ammonium (NH4+). This NH4+ can be stored in cell vacuoles. The plants use this ammonium as their source of nitrogen. One study found the vacuoles of Nitella clavata to contain over 2,400 mg/l of NH4+. Another method plants use to detoxify ammonia is to immediately use the ammonia to synthesize proteins. Toxic NH3 is combined with stored carbohydrates to form ordinary amino acids. Thus, plants that grow well can tolerate more ammonia because they have more carbohydrates to combine with ammonia [Walstad, p. 21].

I asked Tom Barr on another forum about the level of ammonia plants might be able to handle, in connection with new fish being introduced to an established tank and the aquarist was fretting over a mini-cycle. Tom said it would be almost impossible to add so many fish to an aquarium with healthy plants that the plants would not be able to rapidly handle the ammonia.

As a last thought, if you establish the AOB and NOB by fishless cycling with ammonia, and you have live plants that once they start growing will utilize most of the ammonia being produced by the fish and decomposition, would the AOB and NOB not die off for lack of ammonia/nitrite anyway? You see, it just doesn't make sense why you would waste time cycling the tank when the colony of bacteria is going to die off as soon as you have fish and plants.
 
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I have cycled many tanks and that is why your answer puzzled me so. Dr. Tim is my mentor when it comes to cycling a tank and I highly respect him and recommend his techniques. Most of my experience in cycling has come from information taught by him. I would recommend that you watch some of his YouTube videos.
 
I have cycled many tanks and that is why your answer puzzled me so. Dr. Tim is my mentor when it comes to cycling a tank and I highly respect him and recommend his techniques. Most of my experience in cycling has come from information taught by him. I would recommend that you watch some of his YouTube videos.

I have read his papers on AOB and NOB, and I am not so foolish as to argue with someone of his understanding. But even scientists may alter their views as new evidence comes to light. That is how we learn. The fact that his method works does not mean it is the only method that will, as obviously it is not. Live plants are still safer and easier.
 

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