Im sorry how does water get from the 38 gallon to the 2.5 gallon? I want to do something like this but with a 38 gallon and a 72 gallon... any tips?
I have a pump going from the 38 to the 2.5. Since the 2.5 is slightly higher than my 38, water flows back down to the 38 from a mini overflow i built. Hope that helps.