I dose Alk, Mag and Ca via BRS pump. All three pumps are connected to a digital timer that runs 3 times per day for 60 minutes each time. The timer is plugged into controller that shuts down power at 8.45 PH. I also ocassionally add iodine and strontium or kent essentials to calcium mix. A bit unrelated to your thread I dose equal amounts of ca, Alk and Mag. It always balances out some how. If I dose more the corals consume more, to a point it seems to auto balances. This makes it nice in that I only need one timer and use one port on controller.