Russ, you have to double the dosing amount with Randys 2 part. I have figured the cost out and it comes to about $3 per month, and that is on the high side. I go through about a gallon of each part per month. The Calcium chloride only cost $26 dollars for a 5 gal bucket, and it only takes 1 cup of it to make a gallon of mix. Then comes the baking soda, and we all know how cheap that is.
I have not had any adverse affect on the tank using the system, and I have also never had this kind of growth. I have two monti caps that have doubled in size in three months. All my sps and my lps are growing substantially. I will try to post some pics tonight of the growth of a few things in just 6 weeks.
I can't wait to see your reactor next month though. That will be my main interest. As I stated before I may be going larger as far as tanks go, and having a fish room downstairs will make it more feasible to have a ca reactor.