I have a 55 with an overflow. 55lb of live rock, 40lbs of sand, 2 clowns, 1 BTA, golby, foxface, shrip, 3 turbo snails, 3 snails, 6 Hermit crabs, sail fish, long nose butterfly, my amonia is 0, ph is 8.0 buffer is not as high as it used to be but still in the good range (dont remember the number) and nitrait is at 20