I have been bad about testing for magnesium. I tested it tonight since its been awhile and it tested 1020 which I think is low. Do you dose magnesium and if so what brand etc etc? What level do you shoot for?
Mag should be around 1300-1350. I make my own with Epsom salts and MagFlake (magnesium hexahydrate). If you make your own 2-Part solutions, here is a recipe for the mag supplement. If you don't use the 2-Part solutions, here is a different recipe.
Also, here is the reef chemistry calculator to help you determine how much of which supplement to dose.
Rule of thumb I've heard/used is that magnesium should be 3x your Calcium levels, for proper calcium uptake in your corals. If your calcium is low, then your magnesium will probably be low. In other words, if your calcium is at 340, your magnesium is about where it should be expected to be.
Last night my calcium was 380-400, alk: 8, and mg: 1020. So at 3x the calcium I need to be at atleast 1200 mg. Thank for the calculator, I have seen that kent d-tech at the LFS, I guess I will try that. Does anybody have a brand that they recommend?
I also make my own 2 part solution. For now you can get by with just Epsom salt from from the grocer.
From the linked recipte article
"Dissolve a 64-ounce container of Epsom salts (about 8 cups) in enough purified freshwater to make 1 gallon total volume....
The first time it's added, I recommend adding just a small portion and making sure there isn't any problem (such as corals closing up due to stress) before adding the remainder. Make sure corals and other organisms don't get blasted with locally high concentrations of the main ingredients or impurities, or else they may become stressed. "