In all honesty Mike I would not dose any kalk until it is closer to 11 or even 10. I know most reefers run higher then NSW alk, but NSW is like 7.5, so I personally try not to go over 10.
Obviously you are using a fair bit of magnesium, or else you would have major precip issues, either that or your test kit is off.
Once alk gets to 10 and calcium is around 400 or so, then try rescaling yor dosing regime and test every few days to get it right.
Once you have it very close you will nto have to test often. I only test once a month and am never off more then about 0.5 dkh or 20 ppm cal.
You will get it.
