Brown slime in DWC

Whats up guys.

Having a bit of a problem with one of my girls in DWC.
You can see my grow log for more details:

http://boards.cannabis.com/hydroponi...-grow-log.html

Originally she had some weird brownish/clear slime growing in the res. Especially on the air stones. The water was also abnormally cloudy looking so I did a res change and tossed a capful of h2o2. She perked back up after that. Now I checked again and the slime is on her roots now and she is not happy at all. She stopped growing and her tops became real tight almost like they do when they start flowering. She had signs of nute burn before the slime so I backed the ppm down to 550-600 from 750-800. The spots on her leaves seem to keep spreading even after dropping the PPM. Also her leaves feel real dry like shes not getting any water. Using FF grow big and a dose of FF big bloom every other week.

Hope someone out there can help because I cant afford to lose this medicine. Its for me and my father who is really sick.

Forgot to menetion when I did the res change I also changed the airstones and cleaned off the air tubing.

DWC 5 gallon
RW starter plug in PH soaked hydroton inside of a 3" netpot.
Fox Farms Grow Big and big bloom.
Ph - 5.6-6.0 at all times.
Temps between 72f-80f
Res temps are a bit warm 72f-74f
90w LED UFO with four 26w CFLs.
Using tap water that I let sit overnight.