Any recommendation for screen size for a 30g? Planning on stocking with 4 fish, and no skimmer. No clue about cube/day, so if anyone can speak of experience it will be great. Do the dimensions matter so long I match square inches need and correct flow per inch of width? So if I want 12 sq inches and have 105gph I go 3x4, or if I have 210goh I can go 6x2 and achieve the same filtration?