Alk and Calc. help


New member
I finally broke down and bought Calcium and Alkalinity test kits (Salifert) now that I've decided to add some soft corals. According to the kit my calcium is 500+ and my alk is 6.7 DKH (2.4meq/l).

Shouldn't the calcium be around 400 and the alk about 8 DKH? What is the best way to normalize these numbers? I am not dosing kalk, should I? I switched 2 months ago from Oceanic to IO salts.
You have to try to maintain a balance. The water can only get so saturated. If your calcium is really high, it will tend to depress your alk. Same with Magnesium. Ca and Mg, will drop your alk. High alk will drop your Ca and Mg. Mine stays at around: Ca 470 , Mg 1260 (won't go higher) and alk hangs out around 8-11. I use reef crystals salt which a newly mixed batch gives you alk around 7-8, and Ca 450. Instant Ocean will give you an alk about 16 dKH but a Ca reading about 370 mg/L. I dose 2 part B-Ionic daily. 10 ppm of each day to maintain levels.
IO salt is generally low on calcium. Usually tests in the low 300's. Alk around 12-13 dkh.

Let your calcium fall on its own. If you want to raise your alk, use baking soda. Once you get cal and alk where you want it, dripping limewater (kalk) is a fine way to keep it there IMO.

You might want to check you mag levels too as low mag will give you problems.

FWIW, the Oceanic you used before is extremely high in calcium so if you stick with IO (which many do) you will have to keep an eye on your levels.

I got away from Oceanic because I always had bad HA problems and changing salt was my last resort. Since using IO, the algea has decreased significantly.I would have thought the calcium would have come down by now though.