High PH?

[GeoHawk]

Hey I moved about 6 months ago and since moving my ph has been running extremely high. 8.6 morning to 8.9 end of photo period at night. I thought maybe it was ph calibration so I recalibrate my reefkeeper. I haven't really thought much of it until I've noticed that I am having to dose more Alk and callcium (brs 2 part) to keep levels up. This weekend I noticed increased percipitate on my pumps and in my reactors that I've never had before. My magnesium level is 1400 cal 390 and dkh 9.0. 2 main questions.
1. Does high ph like this matter for coral sps/zoas?
2. What can I do to bring it down safely without going too low?

Any info would be most appreciated.

 

[Randy Holmes-Farley]

VERY unlikely to be accurate, unless you are overdosing on high pH additives such as limewater. A two part will not usually do it unless you are adding massive amounts.

I've read literally hundreds of high pH threads, and they all turn out to be testing error if you are not so dosing.

So the first step is recalibration of your meter.

This has more:

High pH: Causes and Cures by Randy Holmes-Farley - Reefkeeping.com