I agree with the water changes but I have to ask if you are seeing any cloudiness at all. From the numbers I'd say you were very close to a precipitation event. Thanks to broomer5 for teaching me the basics here.
Was your alkalinity readings of 17.20 dKH before or after you performed the last water change ? Same with your calcium reading of 400 ... was this prior to or after the last water change ? or dosing event?
At a pH of 8.24 Your alkalinity of 17.20 is too high for the amount of calcium you have. I would consider backing off on dosing for awhile. Perhaps adding calcium chloride to bring your calcium level up to a "balanced" level with your alk.
As the pH rises .... some of the bicarbonate in the tankwater can be changed over to carbonate. Based upon where your calcium levels are at, when this happens, calcium carbonate can form in the tank water as a solid, and precipitate out of solution.
This can easily cause the tank water to become cloudy.. With regards to the kalkwasser, just how fast did it take you to go through about how much kalk water?
Alk/ dKH/ Calcium
0.00 0.00 360
0.50 1.40 370
1.00 2.80 380
1.50 4.20 390
2.00 5.60 400
2.50 7.00 410
3.00 8.40 420 (Near sea water)
3.50 9.80 430
4.00 11.20 440< I personally prefer to be around here.
4.50 12.60 450
5.00 14.00 460
5.50 15.40 470
6.00 16.80 480 <
6.50 18.20 490< your alk is between these two points and it needs to be lowered before a precipitation event happens.
7.00 19.60 500
