I have a 125g I'm going to use for a 3 chamber basement sump for a 180 display. I'm trying to figure out the baffles. How much height does the water usually take going over the top of a baffle ? I'm thinking I'll have about 1200 GPH but some of that split off for the refugium . I'm wanting to keep the center return 36" long so as to do water changes. That leaves about 18" on each end for the overflow/skimmer and the other end for the fuge. I've been doing math and taking into consideration back flow and 6" lowest level for the pump that I should be able to do 30gal water change out of the return section. I'm just trying to figure how high I can go.