Fatman,your not too far away from me,I'm from Daytona Bch.I also use ocean water from time to time.It usually tests at 8dKH for alk and 400ish for calcium.Do yourself a favor,buy a Salifert calcium test and get yourself an alkalinity test(i use Tropic Marin brand).Alkalinity is one of the most important things you should be testing for IMO/IME.Once your calcium and alk become balanced,you dont need to test for calcium that much if you are useing a balanced calc/alk additive like kalk,2 part,etc.By monitoring your tanks alkalinity depletion,you just add a balanced calc/alk solution to correct that depletion.I test my alkalinity once every 2 weeks,I test for calcium 4 to 5 times a yr.