I'm working on the sump for my 210g. I had originally planned on building a sump-refuge out of acrylic but was scared away form this project by the high price of acrylic. My next thought; use a 75g glass tank. I found a 90g for cheap and bought it. Now that it is sitting under my stand, I do not like how much space it takes up, I need to stuff three external pumps and two Ocean Clear canisters under the stand with the sump. A 75g has the same footprint as the 90, just a couple of inches shorter. So now I'm thinking of using a 40g breeder as a sump. This will give me plenty of room for my intended bio-media, Seachem Pond Matrix, and, I think, enough room for overflow when the power goes out. I calculated about 25g reserve space in the tank for overflow and about 10g coming out of my display. Now my concern; I'm going to be running about 3000 gph through this thing, am I going to have any trouble running this much water volume through a 40g tank? I know it works on paper but my brain tells me something is wrong here. Your thoughts?
