When you are first setting up a tank it is far easier to drill 2 holes for sump returns and not really use the full potential of either. Normally 1" drain are rated for 600gph each. I have found that I can consitantly push 1000gph through mine with a durso standpipe. If I were to do it again I would put in 2 and have to throttle it back a little rather than change your mind later and want a extra one. I would also use 1" because of all of the parts that are available for it which is a 1.75" hole.
Good Luck Randy
Good Luck Randy
