yes: you'll note a thread about building a kalk reactor for two dollars and fifty cents: that will provide a diagram. Not at all hard. Basically you stir Mrs. Wages' Pickling Lime into your topoff water at the rate of 2 tsp per gallon of ro/di water---dosage is not finicky.
You do need a decent evaporation rate from your tank to make it work well. I get a gallon a day. That means a gallon of kalkwasser is going into my tank daily. It automatically keeps my alk and cal at optimum 24/7.
The catch is it will only HOLD them at the level of magnesium available, and it doesn't dose that. You have to hand-set the levels by dosing first, then run kalk, and it will hold them there as long as the magnesium stays up and the kalk holds out.