Thanks, this tank has been running for almost a year. It's been through alot, but seems very stable now. I buy a box of catalina ocean water every month and change 25 pct of the water weekly, add B-Ionic for Calcium/Alkalinity (8.2/9dkh). Auto-top off with Kalk which stabilizes the PH, I also have 2 microjet ph's controlled by a wave maker that keeps the coral's happy.