Sounds like my system. 2000k w/ ebb n grow.
I'm using 10-12 pots each run. I use the GH 3-part line (full recipe), plus I add SM-90, Pro-Silicate, and H2o2. http://www.generalhydroponics.com/calculator/index.html
I clean the reservior out and refill with RO water every 10 days. I have to...