Kalkwasser should be dripped into the system, when the lights are off, because with the use of Kalkwasser, the PH will raise around 0.1 to 0.2.
1 drop per second per 100 litre tank volume. 5 drops per second for a 500 litre tank.
Always keep an eye on the phosphate level. The phosphate level should be 0.05 mg/l. I think it is clear, that Kalkwasser reduces your phosphate level.
With adding to much kalkwasser, the phosphate level drops below 0.05 mg/l. If your system needs a high amount of calcium and you can keep your calcium level with kalkwasser, but your phosphate level will drop below 0.05 mg/l, you should feed more or add phosphate.
Do not use Kalkwasser, if your PH is 8.3 to 8.4.
Keep also an eye on your KH level. Add bicarb to raise the KH.
Kalkwasser should not be added where the pump sucks the water in.
Otherwise you will get lots of limescale in the pump. Kalkwasser should not be added at the same spot (and at the same time) where the water from your calcium reactor drips in.
Keep Kalkwasser always in a sealed container and when added, make sure your bottle or whatever you use, will have only a tiny hole to suck air. Just enough to let the water drip. If kalkwasser gets into contact with the atmosphere, the carbondioxide from the atmosphere will react with the kalkwasser, the PH of the kalkwasser drops and the the kalkwasser becomes useless.
A open jar of kalkwasser will be after two days useless!
Only a small amount of the Kalkwasser powder (calcium hydroxide) goes into solution with water.
At 20°C 0.17gram per litre RO water! At higher temperatures, less calcium hydroxide will go into solution.