By far the easiest and cheapest way is to use kalk. As long as your corals don't use more than you can add that is. Otherwise it at least cuts down on how much two part you have to use.
I also have the 2 part frombulk reef supply but I have not even had the chance to use it yet. I do water changes once a week and I just have about 12 small sps frags in the tank. I cant wait til I get to dose.
I dose BRS. I even bought 3 dosers last year so I didn't have to do it, but they still aren't hooked up yet:squigglemouth: They look pretty mounted under the stand though lol
Bought the 2 part, ended up Kalk and water changes are keeping my params stable. I own a drews doser though, and use it to dose mag. Not really needed, but otherwise it would just collect dust and it's to darn cool to let that happen!