PH

[reef-nut]

My 90 gallon has been going for about 4 months now and the ph has been a steady 8.2. The other day I noticed a couple corals not looking so hot and I checked the ph and it was 7.9. What would cause it to drop in a couple days?

 

[Russellaqua]

Did you check it earlier in the day than usual. pH drops over night but rises during the day. Also, if something keeled over on you the decay process can lower pH. Those would be my guesses.

 

[reef-nut]

It was about nine this morning when I checked it. I was ready to do a water cheange before I noticed it and went ahead and did it and now the ph is 8.3.