My fish tank is 70L and I have several fish; Silver sharks (2), Zebra danios (2), Guppies (4), Albino shark (1),Bristlenose fish (1),Black Ghost Knife (1), Tropheus dubois (1), Sword tail (1) and Clown Loach (1). I am pretty sure this is overpopulated, does anyone know the formula to work out if...