I have used Calcium reactors for years (and still do). I've gone back and forth with Kalkwasser. I have a Deltec PF 601 reactor that still cant keep up with the alkalinity and calcium demands of my tank. I've been cursed with getting a consistent effluent from the reactor. If this goes unnoticed, my corals pay the price and I get a huge Alk crash and a ton of STN from the base of my corals. As a result, I've been dosing BRS 2 part using a disjointed measure and dump method. I know the trends of my aquarium very well now. I am going to start to use the profilux doser, I just haven't gotten around to it. The benefits of a doser is maintaining a stable environment, but you have to know what your demand is.
The best part about a two part solution is that it forces you to really understand and "master" (I'll use that term losely since the process is SOOOOO dynamic) the chemistry of you tank. The bottom line about 2 part is that it makes you a better reefer! That isn't my opionion, that is fact....IF you are routinely testing (3 or more times a week) over a period of 2-3 months to understand the demands of your tank.
It really doesn't matter if a solution is ionically stronger, but just what you need to dose. There are a ton of calculators out there. Fortunately, Randy's 2part/BRS is the most popular given its $$$$$$, while it is validated and safe. That makes finding how much to add with any given measurement secondary.
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