Nirvana Blackjack grow

[cehak]

This is my second time trying to grow. The first time I got a thrip infestation and it ruined my crop. Hopefully this time goes a lot better. I just started 1/4 strength nutrients, trying to get some advice on when to move up the strength.

I'm using a 400w mh/hps lamp.
Technaflora RFS kit
5gallon bucket dwc setup

http://i.invalid.com/OTURc.jpg


Here's my plant... the two bottom leaves are burnt pretty bad, not sure if that matters. I read that they typically die fast anyway.

Day 14
1/4 strength nutrients light is 24 inches, not sure when to lower
http://i.invalid.com/Ro68l.jpg

 

[cehak]

Things are still going well. I have a question though, I have one root that is particularly brown, but the rest are nice and white. Should i cut the brown root off or not worry about it?