Recenly I've been talking to representative of a well known company that produces bacteria for use in aquariums. In one of his e-mails he mentioned something that I didn't know - that nitrifying (nitrite oxydising at least)bacteria needed Phosphate. And of course I didn't know that liquid bacteria additives should contain a tiny dose of Phosphate:
"...Our... [bacteria additives]...should have very minor amounts of phosphate in them.
Part of this is due to the culture method and part of that is because the
nitrifiers that do die release the phosphate they have ingested (that
actually gets to be a pretty large quantity when you deal with culture
densities like these).
We do not want to bottle the nitrifiers in a completely phosphate free
environment. The reason is that nitrifying bacteria can have what is known
as phosphate block. Without phosphate as an energy source, the nitrite
oxidizing bacteria simply do not function. This is most common in saltwater
aquariums where they are using purified water and phosphate free salt mixes.
In those situations, nitrifying bacteria simply stop converting the nitrogen
compounds. Usually the addition of even a very small amount of phosphate
solves that problem immediately..."
--Nikolay
"...Our... [bacteria additives]...should have very minor amounts of phosphate in them.
Part of this is due to the culture method and part of that is because the
nitrifiers that do die release the phosphate they have ingested (that
actually gets to be a pretty large quantity when you deal with culture
densities like these).
We do not want to bottle the nitrifiers in a completely phosphate free
environment. The reason is that nitrifying bacteria can have what is known
as phosphate block. Without phosphate as an energy source, the nitrite
oxidizing bacteria simply do not function. This is most common in saltwater
aquariums where they are using purified water and phosphate free salt mixes.
In those situations, nitrifying bacteria simply stop converting the nitrogen
compounds. Usually the addition of even a very small amount of phosphate
solves that problem immediately..."
--Nikolay