We have a 46 GAL bowfront, with a 15 GAL sump and an 18 inch Aquafuge HOT refugium. I'd guess 50 gallons of water after subtractign space for LR and adding fuge and sump. We're using Tech CB buffer. Per the bottle we should dose 12.5 ml of each part A & B (10ml/40 gal) daily. Even dosing 20ml in the morning it will fall from a KH of 9 or 10 to 8 the next AM. Is this normal? How much do other people dose in real life? All other parameters (Amonia, Nitrite, Ca, PH) seem perfect - except Nitrate at 12.5 mg/l.