I think you need to get rid of that ph down for pools. I'm sure someone will pop their head in here and tell you why really soon. But get some ph down made for hydroponics.

I started mine out (2nd set of true leaves) at 150ppm, Technaflora basic 3 part (Boost/Grow/B1 Red) and burned one of them, so, just like everyone else said, take it easy with the nutes.

Just so you know, your setup is almost identical to mine, althought I'm using 5"square pots, the concept is the same. I'm about a month ahead of you, check my thread out http://boards.cannabis.com/hydroponi...ttle-help.html, it may be helpful. Some problems I ran in to with the RR plugs, hydroton, and top feed drip system are well discussed.

Good Luck

...these are 2 weeks+??? Are you sure.