Your PH is also low for coraline growth. Sometimes when you add Calcium to a tank it tends to lower PH so if your adding calcium you have to watch your alk and ph to make sure they stay in a normal range. Remember also not to make large adjustments. Always take your time when it comes to saltwater tanks. Im sure you will get coraline back once you get your paramaters in check.
u mean on your test kit your getting a reading of 0.32 witch equals 10.9dkh 3.89 meg/l.add more of the calcium part until u balance your levels.alk should be 8-9 and cal 400-450.u have to up your dosage but do it slowly until everything balances out.