My sugar/ammonia rock curing experiment

[asylumdown]

Originally Posted by gqlmao

Nice little research project, I have always wondered if carbon dosing could eliminate phosphates and cut down the time on the cycle. I just the cloudiness was the bacteria bloom and your skimmer removed it over the time period. I curious to see how long the cycle will last now with your additional ammonia and carbon dosing.

You have to be careful when you do this. There's two different groups of bacteria at play when you cycle a tank. There's the hetertrophic bacteria that go bananas for organic carbon, then there's the true 'nitrifiers', aerobic chemolithautotrophs which effectively 'burn' ammonia and nitrite with oxygen for energy. They get their carbon by fixing atmospheric CO2, so they don't really need a source organic carbon to grow. The main families of bacteria that do this job are the nitrosomonas (ammonia eaters) and nitrobacter (nitrite eaters)

Many heterotrophic bacteria can also oxidize various nitrogen containing compounds in to NO2 and NO3, and in the absence of organic nitrogen sources, a lot of them can switch to using ammonia. Heterotrophs like bacillus and pseudomonas can reproduce at an alarmingly fast rate, dividing several times an hour, while 'true' nitrifiers can take 12 hours to 2 days to divide depending on conditions.

There's a school of thought out there that believes that when you cycle your tank using an ammonia source that also has lots of organic carbon in it (rotting shrimp, ammonia plus carbon, etc.), what you're actually doing is encouraging a massive population of heterotrophs that outcompetes the true nitrifiers both for space and resources, and something that both prolongs the cycles, and leads to a lengthy period of instability after you think the cycle is 'complete' when the population of heterotrophs crashes. I made this mistake when I first set up my tank. I used WAY too many shrimp, and for the first 3 months I couldn't keep a fish alive but couldn't figure out what was going on.

For what the OP is doing, this doesn't matter, as it seems like they are specifically trying to encourage a massive amount of heterotrophic bacteria that can then be skimmed from the water column, but this is not the same as 'cycling' a tank from a nitrogen cycle point of view