I have 125 perfecto megaflow i'm about to setup in my living room. It shares a common wall with my backroom/fish room so I decided to put the sump in there. Well after a trip to the local Orschelins I ended up going with a slightly larger then planned sump. (The 150 gallon was $140 + tax and the 300 was $204 tax and all so i figured why not. It's a plastic tank and is drinking water safe of course. One of my questions is about pump sizing. I read chompers sticky on the subject but the megaflow tank I have has a pair of 600 Gph overflows. His math indicated id need around a 2k gph pump for my 400 gals of water. I shouldnt have that much head loss since I'm running the lines through the wall with braided water line hose. Call it 5-6 feet total hose length and only about 3 feet vertical. Atm I have a mag 5 pump and a mag 1200gph pump. I was thinking using the 500gph pump would be the better idea since the 1200 would be right at the max my overflows are rated to handle. From some reading i've done larger volumes of water need lower flow rates. As for bio media I was going to use the biowheels already on the 125 that im taking the fish out of and moving to the drilled tank. I was thinking of packing a milkcrate full of pot scrubbies and putting a big airstone in the middle of them for more bio media. (If anyone knows of a thread thats got pictures of other people's setups involving stocks as sumps those would be awesome to.) Any tips and hints would be useful...This is only the second sump tank ive done. Last was a 30g tank i made into a sump...so this is a Bit larger. With nothing to glue glass to!