just make sure you are not over adding anything. Go out and get the testers for Ca and such. It is very likely, depending on the salt you are using, that you already have everything you need. In which case, you will throw off your system.
for example, by having Ca that is too high, it will most likely lower your ALK, makeing shifts in your pH common and larger. This is never a good thing, esspecialy to delicate inverts and corals.