Well i have to say that I Love to use Bio Balls and I do understand that some people read NIT in the system. I have run my system for 5 years and have never have a NIT problem. but i do use a filter sock as well for my Bio balls. My filtration is in 5 steps. first is my socks and filter fiber cloth (aka SOFT Filtration) next it hits my bio ball drip plate, 3rd it go's in to my Bio Balls (AKA Bio Box), after that it go's into my mechanical area, (aka Mech Filter system) were i have my 2 skimmers rated at 400 gallons each along with my 25w UV that i only run for 1 hour every 6 hours, and 2 Phos Ban 550s with carbon and GFO, and my last stage is the return. I Like chimi pure and i know it is a nice thing to have I personaly Love Bio filtration as a main filtration and I have never had a problem with NIT at any time after my cyckle. Just putting in my 2 cents is all.
gotcha - are you using any form of refugium in this setup?