Short run, long run, whatever. Kalk is super cheap if you use Pickling Lime. It's the same stuff as Kalk powder that you buy at a fish store (Calcium Hydroxide), but it's about 1/4 of the price. You can find it with Canning Supplies at grocery stores, Wal-mart, some hardware stores (I got it at Rounds Hardware on Main St. in Stoneham).
You'll use about $10 of Kalk per year, so it's much much cheaper than B-ionic, and you can easily put it in a doser to dispense unattended, as opposed to pouring in B-ionic everyday. I think you'd have to be careful with auto-dosing b-ionic in separate containers because they probably wouldn't drip exactly the same, unless you had dosing pumps, so the Ca/Alk might not be balanced.
The main drawback to Kalk is that you can only add as much Saturated kalkwater as you have evaporation. So if you add 1 gallon of top-off water each day, you'll be able to add 1 gallon of saturated Kalkwater each day. If that's enough to keep up with your demands, then you're set. Otherwise you'll have to supplement with a little B-ionic. You'll still save a lot of money over just using straight B-ionic.
