Ah, so you'd like to see what kind of neglect / abuse it takes to cause a Nitrifier community to lose its ability?
Yes lol, probably if left for a few weeks or so regardless of conditions they’ll bounce back. Might take some time but would bounce back yeah whether starved of just ammonia or both ammonia + oxygen.
IMHO I do not think the study suggests that stability be avoided. It was not expected that stability would do anything with only ammonia as 'food'. Once other items are added with ammonia - it will be interesting to see what Stability does or doesn't do.
Actually - in low O2 - or low Ammonia conditions, Nitrifiers go dormant - and once O2/ammonia is restored, the bacteria rapidly recover. If you look at my experiments - done near the start of this forum - After a month of 0 ammonia, upon re-addition of 2 ppm, it was rapidly removed (suggesting that the old bacteria 'reactivated'). I did not use an anoxic condition specifically - but low flow is known to slow the growth of nitrifiers. If left for too long - or there are anaerobic bacteria present - my guess is that nitrifiers may be killed in a pure anoxic condition (picture a canister filter that was shut off for a month - and the smell when you open it).
I've often considered what happens when power shuts off to something such as a canister filter. My assumption being that autotrophs consume all DO and produce nitrates along with nitrites that may not have completed due to absence of oxygen. Heterotrophs then take over converting nitrates to nitrogen since there should be carbon present along with sulfur. That end result creating the smell which all can be gassed off once restarted by ensuring the effluent directed at the tank surface. The sulfur angle not something I've focused on but aware that dentritators seem to prefer it over nitrates. I could be completely wrong but if bacteria can lie dormant in a bottle then I see no reason why they can't inside a canister. Speaking of both autotrophs and heterotrophs. Bit sure why lack DO would otherwise affect autotrophs (specifically bacteria). Having no lungs and merely requiring DO for a chemical process is how I understand we get bacteria in a bottle and what was quoted directly by Dr Tim.
The difference in my mind would be that in a canister filter thats shut off and left - let's say for a month is the amount of organic matter that is present as compared to Dr. Tim's. And you're correct I think - that all of the O2 would be used up. There are multiple potential degradation pathways. It would surprise me if obligate ammonia autotrophs would survive in that chemical soup - but I guess it's possible for them to be dormant.
Here's Group 2 data. It's kind of incomplete but we'll see why.
This experiment has managed to keep things interesting. I expected this first round - ammonia only - to be mostly on or off - does or doesn't, but different patterns keep showing up.
Group 2 Total Ammonia and Nitrite
One and Only, MicroBacter Start XLM, and Caribsea Arag-Alive all responded to ammonia-only during the measurement time frame, but not in similar ways. The Arag-alive live sand was the only one that cleared ammonia and cleared Nitrite shortly after. MicroBacter Start XLM cleared ammonia at about the same rate as the live sand, but it processed seemingly no nitrite. The NO2 stayed pegged near max theoretical - give or take measurement noise.
Dr. Tim's One and Only did definitely respond, but just barely. Poor result for what was supposed to be the trusted positive control. Actually, I'm going to argue against this "poor result" interpretation in just a minute.
The negative controls of "sterilized" and Tank water did precisely nothing to ammonia over the 25 days, and API Quick Start was indistinguishable from these do-nothings.
Group 2 Final Nitrate and pH
Caribsea Arag-Alive was the only one that cleared ammonia and nitrite in the 25 days, so was the only one that I measured final NO3. The final value was in agreement with classic nitrification - the amount of NO3 produced is within error of what would be expected from total conversion of all ammonia to NO3.
The pH shows the same 3 products as being active as the ammonia & NO2 data: Caribsea sand, MB Start, and at the very end - One and Only shows some pH move relative to the non-responders. (The drift down of the pH of all samples is due to the CO2 environment of the indoor space. Over time, with opening and sampling the indoor CO2 lowers all sample pH.)
Commentary
Little needs to be said about CaribSea Arag-Alive and API Quick Start. Quick Start joins the non-responder product Seachem Stability from the first group as products that do not seem to activate under the restrictive conditions of just ammonia and moving water in the dark. Caribsea Arag-Alive joins Group 1 products Nature's Ocean live sand and Biospira as products that work exactly as traditional nitrifiers are expected to.
MicroBacter Start XLM is interesting in how a fairly robust ammonia oxidation to nitrite is coupled with no apparent oxidation of NO2->NO3. Looking closely at the Nitrite chart above, NO2 is produced around day 8-9 but by day 26 there is still no clear decrease of NO2 below the theoretical maximum. I've seen many discussions of this possibility, but this is the first demonstration I've seen firsthand of a sample that could process ammonia well, but was seemingly incapable of processing NO2.
Let's talk about One and Only. If we were looking for evidence that a product had the right bacteria to process ammonia, but was too nutrient deprived by the conditions to expand in population, we'd expect that it should start processing ammonia, but be unable to accelerate (exponential growth), and instead continue processing ammonia at a slow steady tiny trickle for an extended time..... and this is very much what One and Only data looks like.
Here's One and Only showing ammonia (solid lines) and nitrite (dashed lines) on the same chart (different y-axis scales).
If you track the NO2 (dashed) lines backwards from day 25 the NO2 production starts around day 15, but even after 10 days (15 to 25) of verifiable ammonia oxidation, the ammonia level has only decreased from 2.4 to 2.2 ppm. This suggests a small, active population of nitrifiers that has great difficulty reproducing in these conditions.
I'll plan to give the bacteria that were unable to clear ammonia another crack with just some PO4 added, and see how many of the non-responders rapidly respond. I don't expect the totally dead to snap to life, but the struggling might struggle much less.
I was mainly going off of known research, such as this: https://academic.oup.com/femsec/article/58/1/1/468326.
I don't think Dr. Tim's is the 'gold standard' - based on the last study by @Dr. Reef. The smell after opening a canister filter after a month is methane and sulfur compounds. It's not due to death of nitrifiers - it's due to anaerobic decomposition of the junk in the filter.
So I think there are 2 conditions. 1. Obligate autotrophs have no O2 - IMHO - they might go dormant. 2. Obligate autotrophs have no ammonia - they might go dormant. 3. Obligate autotrophs have no O2 AND no ammonia. I don't know whether they would survive. Hope this helps
I do not see a reason why they would not survive.
OK. all good. the problem here IMHO is that no one really knows what bacteria are involved - for example - the Archeae etc. The new news - on cycling is not as one person says based on quarantine procedures - instead its based on which bacteria neutralize ammonia
That is correct, in that no one really knows what is involved - or at least long term in a person's aquarium, what ultimately engages in nitrification. And while it does seem like some type of nitrifiers can only utilize ammonia, others have been proposed to be able to also perform ammonification and derive ammonia from organic compounds like urea, further complicating matters.
That's a great thought.
Yeah. I intended to use biospira as the control for group 1, Dr Tim's for group 2, Fritz turbo start for group 3. Partially so I could test them all while acknowledging that we sort of already "know" what was going to happen. Also, frankly I was worried that some product groups could contain all non-responders, which would make it a little unclear if everything was OK with the setup.
Yes. I'll keep watching it. I can't actually be sure that this is not exponential growth, the amount of ammonia consumed and nitrite produced is so tiny after all. But if it is an exponential curve, then the doubling time of this growth is absurdly long. There has been detectable nitrite for 10 days, but still only dropped ammonia by a couple of tenths in that time.
