[Randy Holmes-Farley]

I guess my worry is that if I'm not using enough alk/calc in the system and topping off with the kalk is going to vary on my evaporation rates.

How do you guys combat that?

There is a negative feedback loop that prevents such issues from being a big deal, IMO.

As the alk rises and the pH rises, demand in the tank for calcium and alkalinity also rises, offsetting additional inputs. The opposite happens as alk declines, and demand almost disappears as alk drops to 6 dKH or so.

You may want to change the concentration of limewater with big seasonal differences in evaporation, but day to day it is not a concern, IMO.

The aqualifter might be a bit fast, but some folks use it. How much gets added with each triggering of the float switch? That's the big question.