How can I keep my ph up?

[RuGlu6]

not my quote but makes sense.
http://www.advancedaquarist.com/issues/nov2002/chem.htm

Unfortunately, calcium and alkalinity are linked in many ways in reef tanks, and these links can lead to serious problems if they are not fully understood. If, for example, you add too much of a calcium supplement, you will drive down alkalinity as you get precipitation of calcium carbonate in the tank. Likewise, adding too much of an alkalinity supplement can result in reduction of calcium. Consequently, trying to correct one problem can cause another. Moreover, if you try to correct a calcium or alkalinity ?problem? with the wrong type of additive, you might accomplish nothing more than creating limestone in your tank.

[Dolf]

I'll take a quick crack at this mostly because I disagree with disregarding PH levels. First, I believe that low magnesium levels can contribute to a low PH reading, so that is one thing to keep in mind. Also, if you are one of the reefers who loves technology, running Ozone and U.V can also cause a reaction (read oxidation) which can contribute to low PH. Even if you only run one or the other they can have a malfunction (buildup in the quartz sleeve for example) so you may want to unplug it for a few days to see if that helps. A buildup of detritus somewhere in the system can contribute as well. The problem with ignoring PH is that it is usually indicative of a different problem somewhere- but that is just me.

A calcium reactor will also keep your PH a little lower than it otherwise would be due to the use of CO2. From Eric Borneman (yeah, I quote him and Dr. Ron a lot...)
“The studies I have read on this suggest that higher pH is better for coral growth, even if it not natural. I would have to go back and look, but I think 8.6 was the highest calcification rate for the species studied."

[Aquattro]

Or you could throw your meter away, no more problems!