Originally Posted by 0001
also is it bad to have to much filtration? i just wonder cause i have 2 filters in this 20 gallon both 150gallon/hour is that to much?
Most likely yes; but it does depend upon the fish species and bioload. Filtration is best when suited to the fish in the aquarium. Water flow is the big issue here; some fish need currents (Hillstream Loach is an obvious example), but other fish should not have them (gourami, angelfish, many forest fish such as the tetra, rasbora, etc) because they are stressful for the fish having to constantly battle currents day and night. This wears them down and weakens their immune systems.
Filtration also depends upon plants; live plants do the filtering, so the filter is only there to gently move water around and keep it "clear" which is different from "clean."
Then there is the bioload, the number of fish in the tank.
It sounds like you have way too much, but I would need to know the fish in the tank to be more definitive.