I am having trouble with keeping my ph up in the 8.1-8.3 range. I have to adjust the ph at least twice a week to keep in in range. I have a 35 gallon tank half filled with live rock, crushed coral substrate and 2 puffers, 1 coral beauty, 3 chromis and a wrasse(christmas I think). Can any one please help me to find a way to keep the ph level more constant ? thanks