Thaw the mysis and then rinse it in RO
water before feeding it to your tank. that will help remove all the nasty stuff.
I've been running my system for over 3 years and have only been dosing my tank for the last 6-8 months. I use a 2 part system for calcium and Alk
. I do this because I have a 55g frag tank full of SPS
corals as well as a display tank full of sps
corals. Your tank doesn't need supplements. The salt mix will take care of everything for you. Your LFS
wants to sell things so they are going to suggest you add all kinds of things to the tank.