The pH crash shut down the nitrification bacteria. Whether or not it killed them is likely to be a lot more complex, with large individual variation depending on the the already stated length of time exposed to the very acid conditions (optimum for these FW bacteria is 7.5 and above), the age of the colony (for some reasons not fully explored or explained, new colonies are much more sensitive than long-established ones), and no doubt other factors as yet unknown. The ammonia oxidizers at least do have a non-spore idle condition during which they are not dividing and not comsuming much either, which is likely a response to inadequate or suboptimum living conditions, but how long they can hold there is poorly understood/studied, as is what reactivates them. The net is that your nitrifiers may or may not have been killed, and as usual, the only proof is how well and quickly they recover.
Many folks have detectable and non-trivial nitrate in the tap water. This is the limiting factor on how low you can maintain nitrate titer in unplanted tanks. In high-light carbon-supplementd planted tanks, this obviously it is less of an issue, but would still be dependent on the levels in the source water. In lower tech planted tanks, the situation is more similar to unplanted situations- it depends on the titer from the tap as the nitrate requirement of the plants would be significantly lower than in faster-growth situations. As you do not report this from other tanks, and previously had very low nitrate, it likely is not an issue in this situation.
Prime and other such complexers are pretty stable. The ammonia is likely there until the bacteria or plants split it off from the complexer. There will eventually be bacterial or other breakdown of the complexer (chemical) itself, but any study on that is likely to be and remain highly proprietary. The Seachen test can distinguish between complexed and free ammonium ion. I don't know of any other which can. I don't use the test myself.
Nitrite toxicity is fairly pH independent. Ammonia toxicity in tanks is highly pH dependent. This is all due to the balance between the dissolved gas NH3 and the ionic form NH4+. The ammonia NH3 is toxic, the ion is not very toxic at all. The balance between the two forms is pH and temperature dependent. There are tables on the web which give the relative proportions based on pH and temperature, but I don't have the URL handy. WetmanNY's like was broken some weeks back and I don't know if he has gotten it restored.
I am uncertain of the Prime effect, if any on nitrate. What would be the point? It is already fully oxidized.
Nitrite is not fully oxidized, but its toxicity is easily blocked by chloride ion (Cl-) from ordinary salt. It is a simple competitive inhibition for binding sites. I don't know if Prime includes chloride.
Many folks have detectable and non-trivial nitrate in the tap water. This is the limiting factor on how low you can maintain nitrate titer in unplanted tanks. In high-light carbon-supplementd planted tanks, this obviously it is less of an issue, but would still be dependent on the levels in the source water. In lower tech planted tanks, the situation is more similar to unplanted situations- it depends on the titer from the tap as the nitrate requirement of the plants would be significantly lower than in faster-growth situations. As you do not report this from other tanks, and previously had very low nitrate, it likely is not an issue in this situation.
Prime and other such complexers are pretty stable. The ammonia is likely there until the bacteria or plants split it off from the complexer. There will eventually be bacterial or other breakdown of the complexer (chemical) itself, but any study on that is likely to be and remain highly proprietary. The Seachen test can distinguish between complexed and free ammonium ion. I don't know of any other which can. I don't use the test myself.
Nitrite toxicity is fairly pH independent. Ammonia toxicity in tanks is highly pH dependent. This is all due to the balance between the dissolved gas NH3 and the ionic form NH4+. The ammonia NH3 is toxic, the ion is not very toxic at all. The balance between the two forms is pH and temperature dependent. There are tables on the web which give the relative proportions based on pH and temperature, but I don't have the URL handy. WetmanNY's like was broken some weeks back and I don't know if he has gotten it restored.
I am uncertain of the Prime effect, if any on nitrate. What would be the point? It is already fully oxidized.
Nitrite is not fully oxidized, but its toxicity is easily blocked by chloride ion (Cl-) from ordinary salt. It is a simple competitive inhibition for binding sites. I don't know if Prime includes chloride.
I thought what she was getting at was that she had such a high concentration of Chloramine in her water that even after treating and nullifying SOME ammonia, there was still SOME LEFT in toxic free form. Does her test only give the Total Ammonia count? I personally use PRIME and also use a Seachem Ammonia test, I NEVER detect ANY ammonia .....before, or after treatment. That is why I misunderstood.
I'm hoping next week goes much better.