pH control

[Newportreefer]

I just checked the pH in both my reefs with the Fastest kit and whereas they had been running around 8.3 both were off the scale, over 8.5. The lights have been on for about 4 hours when I did the tests. I don't want to turn the lights off due to the corals. What do you do about that?

 

[Len]

Are you dosing anything? I'd also confirm your test results with another test kit or probe. 8.5 isn't terrible, but I'm somewhat surprised the highest reading for a saltwater pH test kit goes only to 8.5.

 

[Newportreefer]

I put Seachem's Reef Advantage Calcium in the top-up reservoir and dKH buffer directly into the overflow about every other day.
Recently I was given a pH meter for my bd. It shows that the pH is 8.0. I checked the calibration and it was okay so I don't know. Everything looks fine.
The Ca is around 425-450 and the alk 3.8.