The bottle of reef Complete actually says on it, Ca levels above 400mg/L is NOT recommended. The bottle also recommends using Reef Carbonate or Reef builder in conjunction with the Reef Complete. "Reef Carbonate is a concentrated (4,000 mg/L) optimized blened of carbonate and bicarbonate salts designed to restore and maintain alkalinity in the reef aquarium.""Used as directed, Reef Carbonate will no deplete calcium, magnesium or strongtium which usually tent to precipitate with increasing alkalinity."

You may want to buy a SeaChem Ca test kit as it does measure all types of calcium, including calcium gluconate.

Yes, that's what my bottle says. I really wasn't trying to go over 500. I just didn't test for Calcium regularly and kept dosing and dosing thinking that my Calcium was being used up. My mistake. I haven't been adding any polygluconates into my tank though (which would be the Seachem Reef Calcium product). Do you think the SeaChem Ca kit will give me more accurate results than the other 2 kits? I could try it I suppose. Wouldn't hurt.

Good old baking soda works wonders for raising alk. Just add it slowly and your fine.