Upon noticing lethargic behaviour in my Clownfish recently I checked the PH level on my established 72 gallon saltwater/reef tank. Reading is well over 8.7 (sample is dark purple). Sample taken at source is +/- 7.5. Sample taken when marine salt added to source water is immediately reading over 8.7 (purple) and after 24 hours(well mixed and pump agitating) is still over 8.7. Other tankmates are an approximately 9" Regal Tang, 6" Yellow tang, 3" Flame Angel, 3" "Other" Angel and a small crab (no corals are present). These inhabitants are active and eating well although the Regal Tang is somewhat faded in colour. Temperature is about 79 degrees and nitrate, nitrite, ammonia results are normal. I have however noticed test result for calcium is ,by calculation, 320. Performing 10% water changes weekly, up to 25% since noticing PH issue. Anyone have any suggestions on how to address this issue? I am hesitant to begin treating the water with chemicals.....yet. Thanks in advance for your input!
