Pure epsom salts is simpley magnesium sulfate and can be used to suppliment the Mg
in the main tank if your saltmix is defficient or your tank simpley uses up faster. The supps you get at the LFS
are Magnesium Chloride diluted in RO
water. The small amount of sulfate salts added instead of chloride will be of no concern.
Test with an Mg
test kit (I use Salifert) and dose as mentioned before. 1 tablespoon per 50 gal
actual water volume. Be sure if in the main tank it is not added close to a buffering product or it will bind with the carbonate and precipitate. Don't exceed the 50 gal
ratio in one day but it is safe to dose daily until Mg
levels are reached. Add predissolved several hours after the buffer but before Ca
additions. If using a two part liq supp, you most likley won't need much if at all.