Originally Posted by Cb24
What percentage do you normally do for a 55g?
20-25% is the norm I think. Some do 50%.
Example. In my 75 gallon I do 25% weekly's. once a month I'll do a 50% or bigger. I have a heavily stocked tank.
I'd say whatever your tank calls for. If its a heavy bio load do more. Light bio load maybe less
Testing your water parameters will tell you what needs to be done. You may do 25% weekly's and find its not enough.