PH refuses to go up!!

[hawaiiguy]

I'd agree with everyone else, your pH looks good. Your probably right, 8.3 is best but with your tank at 8.1, it's close enough. I don't think its worth messing with and taking the risk of sending pH skyrocketing out of range due to a mishap...

Perhaps the corals are struggling due to something else. What sort of lights do you have on them? How long are the lights on?