When DIYing an overflow, does it matter how big the box is? or just the pipe that goes into the sump? Im doing two overflows, one for a 55 and another for a 25. for the 25 i wanted to to have a 4x4x4 inch boxes and for the 55 8x4x4 inch. will these be large enough if i drilled the appropriate size holes for the water flow? thanks.