how to mix 5gallons of kalkwasser?

The way I introduce kalk in my system is very simple. My top off container is a 15 gallon glass tank. It use a aqua lifter pump attached to auto top off. This adds the water at a slow rate which doesn't cause a high PH spike. When the tank is getting low I add more RO Water and Kalk (unplug auto top off first) plug in power head and let mix for about an hour. Than let settle for about 2 hours plug auto top off back in. I do this about once a week when I do my weekly water change and skimmer cleaning. The tank has a cover on it and would not say it is air tight, but keep dust out and evaporation down. Also I not saying this is as good as a reactor, but is a cheap alternative.