One thing to try with fixing your PH is if you have any lights on your sump growing macro algae run them opposite of your display tank... I have a GE daylight coil PC in a cheap Home Depot cone reflector over my Cheato in my sump, and it holds my PH at 8.05 all night, and it rises to 8.07 during the day, and never swings more than that... My display is a 280G and sump is a 110G...
I also had a problem with my Zoas not opening and it was stray voltage.. I bought at Home Depot, a "Greenlee" quick voltage meter... It looks like a big green magic marker, with a light/beeper on the end and a little tab for putting in a socket to check for power... They are very sensitive and will even pick up static electricity from your clothing if you rub it on your sleeve.. I put a Corallife titanium ground probe in the tank, and touched the meter to the ground plug that is supposed to go in the wall.. It went CRAZY, flashing and beeping.... I started unplugging things until it stopped beeping.. I found a Koralia 4 that was putting full voltage into the water, yet it was still running like normal.... Within a couple weeks everything was back to normal :-) upon later testing in a bucket, and not my tank :-) I found that the Koralia was putting a full 110volts into my tank..... Remember fish are usually not be affected by stray voltage because they are isolated from it, unless they swim up and put a fin on something grounded and touch a fin to the water at the same time :-) LOL
Adam
P.S. Sid the kid saved our butts big time in Vancouver :-) Thanks for training him down there for us :-) LOL