my gsp (green star polyps) seem to go in cycles because it's polyps will look black and then go away for a day and come out fine but the polyps seem to be reducing
can you post your exact parameters? by air pump do you mean like a bubble stone? those usually arent used in saltwater aquariums, not really sure why, i thinks it messes with the ph. what kind of lighting do you have / how many watts?
Airstones shouldn't effect ph much but usually you don't use airstones because salt creep is horrible because of the airbubbles popping at the surface.
Airstones are a bad idea because they trap microscum and O2 and put it to the surface. It actually removes O2 in the long run and can lead to lower PH and health problems. I would remove it,