calcium levels "fixed, thank you"

[martym]

Why can I not maintain 400-450ppm levels??? I drip calcium hydroxide( I don't know how old it is it was given to me) everytime i top up. I just finished 2 gallons mixed with 3tps kalk dripped for 20hrs and my Ca is 220ppm. DKh is 10, Ph around 8.1-8.2 ( I can't wait to get a pinpoint I can't stand matching colors) I only have 4-5 small hard corals, but I do have a lot of pink and green coraline algae forming. Should I add turbo calcium to get the levels back up? About a month ago I was around 380-400ppm Ca, but I just can't maintain it. It might be time for a calcium reactor, but I would never be able to convience my better half of that.
Thanks for the help