safe to remove one filter?

[2wheelsx2]

HOWEVER, since he has an existing colony, at every step of the way, the necessary bacteria to eat the ammonia and nitrites exist. There will be no spikes.

Tim

I'm sorry, but I can't agree with this. If you start out with 100% of the bacteria with 2 filters and you remove 1 filter, how can you instanteously support all the ammonia. Notice I never mentioned a spike, but rather, and inability of the colony to keep up with the load. It won't be an immediate spike, as ammonia builds up gradually, and the bio will build up gradually too.

No different than adding fish. If you have 6 fish with an established filter and then add 6 more, the same thing would happen.

[tcyiu]

I'm sorry, but I can't agree with this. If you start out with 100% of the bacteria with 2 filters and you remove 1 filter, how can you instanteously support all the ammonia. Notice I never mentioned a spike, but rather, and inability of the colony to keep up with the load. It won't be an immediate spike, as ammonia builds up gradually, and the bio will build up gradually too.

No different than adding fish. If you have 6 fish with an established filter and then add 6 more, the same thing would happen.

I don't disagree that there will be some fluctuation. What I disagree with is the notion that this is the smaller equivalent of a cycle. Cycles take a long time and produce deadly concentrations of ammonia and nitrites before the bacteria can catch up.

The existing nitrobacter and nitrosomas in the OP's tank will take about 12-13 hours to double. They will use the excess ammonia to create the extra energy for needed for cell replication.

This is why we can make reasonable changes to stocking levels and the fish don't die from "new tank syndrome." For example, earlier this year, I moved 6 sub-adults to a tank containing 3 adults in one fell swoop. The bioload was essentially tripled, but yet, there was no sign of distress at all (except the normal pecking order stuff). The bacteria had plenty of room to grow, and suddenly more energy sources to do so.

The self balancing takes less than a day, and a lot of the excess will be converted to energy for new cells. Not quite what I would call a cycle or a mini-cycle.

That's all I'm saying.

Tim