I found that when I used vinegar to boost the calcium levels, two things happened.
First, the alkalinity gradually eroded because the pH was no longer as high.
Second, I ended up with nuisance algae problems including cyano that went away when I quite dosing kalk with vinegar.
Now, I use Randy Holmes-Farley's DIY supplements to increase any level that gets too low. The calcium chloride to boost calcium, the magnesium chloride hexahydrate to boost magnesium, and the baked baking soda to boost alkalinity.
Once up, the kalk is used to maintain.