it is going to be on a 10 gallon tank, the sump tank is going to be 5 gallon. the overflow box is going to be 5" wide. the shpoin will be 5" wide and 0.5" space. This will give me a VERY large flow. BUT, when i get a bigger tank this willl be GREAT. i knowi this is over kill for evena 35 gallon or even 50 gallon, BUT it is something to do, and i love building things.