Since Alkalinity, Calcium and pH all need to be balanced, I bought a Calcium test kit. The Calcium seems to be at 545mg/l! That is very high. Since my Alkalinity is only 7.0 dKH, I decided to make use of Kent Marine’s Pro Buffer dKH. I started adding 35ml to the water daily. I also stopped adding kalkwasser. The idea is that since kalkwasser is a balanced supplement, I first need to get the proportion of Calcium and Alkalinity right then I’ll resume adding kalkwasser. I think the different salt I used as well as the RO water to fix SG messed up the balance.