How to lower my ph levels

[reeftank50]

I am having trouble with my PH levels. My ph monitor reads from 8.8 to 9.0. I can't get the ph down to 8.3. I have a 100 gal reef tank with a little over 100 lbs of rock. I am also running a calcium reactor. Any idea would be helpful.

Thanks,

Steven

 

[THE ROOK]

When was the last time your monitor was calibrated?

Make sure to use 7.0 & 10.0 to calibrate.

 

[reefworm]

ditto on making sure your probe is calibrated. If so, here's some further info that should help.
http://reefkeeping.com/issues/2007-05/rhf/index.php