I should have mentioned that I bought the cbs as a mated pair, but thanks for double checking me!
Are you able to expand on how the tank size makes a difference? I really am asking as a learning point, not trying to argue with youI thought maybe with a steady supply of copepods I would be OK. Or is it because I am running fowlr?
It is because of the rate of eating copepods. Mandarins eat constantly and the reproduction rate of copepods will be exceeded by the number consumed. My rough estimation of the minimum tank size to reach equilibrium (number produced = number consumed) is roughly 75 gallons. Obviously, any other fish that consumes copepods will make the problem worse and the equilibrium gallonage higher.