[RTR]

Very well done, Dave, good article and good work.

I am glad that you noted that are lots of ammonia and nitrite eaters in the world, and that the trick is to get the right ones which establish long-term colonies in FW tanks. That is the key difference in commercial bacterial starters.

Somewhat off-topic in a FW article, but perhaps worth mentioning that the same FW bacteria persist and function as the nitrogen cycle bacteria in low-specific gravity brackish water up to about 1.008 specific gravity. Above that approximate value, other species start taking over the job. The same qualifiers apply as to the FW cycling - the bacteria are more sensitive to the KH (and thus the pH) of the water than are the fish in the tank. This is most important during the cycling process (colony development) rather than after the colony is established. For many complex reasons, the developing colony is more sensitive to pH crash than a mature colony will be, especially the nitrite eaters IME. Part of the general sensitivity of the cycle bugs is that their optimum KH/pH and temperatures are not quite the same as the levels where most tanks operate. Normal tank ranges are acceptable and fully functional, but not optimum.