http://reefkeeping.com/issues/2006-11/rhf/index.php#3

I keep this one handy these days. It's always good to go back and review your problem no matter how long you've been doing this. Sometimes it's little things you forget that can help out drastically. Off to run some O3 do a little slurry. A couple of TBSP in my tank raises my PH approximately .14 and I think right now it's in the high 7s.