I know it's cheaper, but is this a safe substitute for Kent's Turbo Calcium? I add 1 tsp of turbo calcium per 5-gallon of salt mix to compensate for the low CA in Red Sea Salt. I'm getting low on TC now, but overall I really don't use that much, so paying on-line price for Kent won't affect my standard of living. But I won't mind saving a few bucks if dowflake will do the job safely.