I've read lot of horror stories about under current style systems and living organisms. Seems they like to get out of control. Do you have any recommendations to what I should be adding?
Cap's bennies are an excellent choice, but really use several- plus a handful of earthworm castings. No, wait. You have no place to put them in your rdwc, so brew aerated compost tea, add castings, in it, and then dilute 10:1 before pouring a cup or so over your hydroton in each site. Repeat regularly.