i use pickling lime and vingear at rates of 40ml vin to 2 tsp pickling lime to 2L of water in my top off. makes my sps happy. I have a Ca reactor with CA media and mag media. I use to does calcium chloride for calcium but it scares me becuase the chloride can build up in an aquarium over time. both methods are cheap solutions to dosing. you could also use powder KH and Ca but it takes a lot of time and labor.
good luck, your corals will thank you.
kurt
75gal 6x54w t5's on icecap slr's 3 blue +, 1 pro color, 1 ge 65k, 1 uvl spuer atintic, iwaki 40rlt return, mak 4 on closed loop to om super squirt, mak 3 on etss reef devil, jbj artica chiller, aquamedic calcium reactor, DIY Kalk reactor, DIY media reactor, currently running half phospahte/half carbon.
Live in Uvalde, Texas. On the fish hatchery!