HELP!! pH is 8.5!!

[Delphinus]

8.5 is a perfectly normal number for a reef during daytime hours (for kicks, test again in the morning before lights on and see how far it's dropped - a "typical" reef might fluctuate between 7.8 to 8.2 with a calcium reactor, and maybe 8.0 to 8.4 without. But each tank is different. Heck, you could have 8.6 and not worry about it.)

Also, something to keep in mind, pH in and of itself is almost a meaningless number. Think of it as a composite index like the Dow Jones or something - if it's up it means more stocks are doing well, if it's down it means more stocks are not doing well, but it doesn't tell you what stocks are up and what are down. pH is little like that. It's the result of other parameters coming together and different things will pull it up or down, by itself it doesn't tell you what is what. I don't even bother testing pH in my tank anymore. Focus instead on things like NO3, PO4, Ca, Alk and Mg. My $0.02, HTH.