Willie I used Kalk for my first year and it worked great in terms of a balanced additive for managing ALK+CA, but I got tired of it messing up my ATO pump and the ATO water level sensor. There's probably a cleaner way to dispense kalk or use more powerheads to try to mix the kalk when it is dispensed, but I thought it was more work for myself personally in my setup. I have a 20G ATO and would just mix it once every time I filled it up.