Microbac7 and biopellets

[dcw1sfu]

I just put my biopellet reactor online with about 1/3 of my total volume of pellets I will be using. I have a 60gallon and sump how do I feed the pellets with microbac7? Do I put it directly into the sump where my return pump/reactor pump is or do I pour into the actual reactor? Also how much would I use and do I need to mix it with Ro water?