Dosing - kalk can`t keep up

I've been using kalkwasser for my ATO water for the last several years.  I make a fully saturated solution - 2tsp/gallon.  My evaporation rate is 1 gal/day.  At that rate, the kalkwasser is no longer sufficient to maintain my calcium and alk.  I'm dosing about 45 ml/day.  So, as that is a pain, I need to make a change.
I think that what I need to do is switch back to 2 part solution - and use a dosing pump.  I've looked at the Drew peristolic pumps.  In addition to the pumps, I'd also need to get another PC4 for my Reef Keeper lite, for controlling the pumps.  Does anyone have experience with the Drew dosing pumps?   Any other low cost, automated (those two words don't go well together!) solutions that I'm not thinking about?????

 

so cal tropical fish outlet has a aquahouse dosing pump for 79 dollars looks like a possibility

 

what about picking up a CA reactor? Can be a bit pricey upfront, but definitely easy to maintain.

 

Thought about a calcium reactor, but more than I want to spend, and also more complicated I think.

As for the BRS dosing pumps - are thye quiet???