Root Rot? Or Nutrient.... uh... globbing?

Hey guys, I have my lil White Widow (freshly topped!) about 2 weeks into a closet (5gal) DWC under a 250W T5 HO.

The other day, after a few days of fresh water res (had some other issues), I picked up some Hygrozyme and mixed it into the reservoir with a fresh load (about half-strength) of some FF Grow Big. Starting pretty much the day after, some of my roots started looking a little bit tan/brown. Now today, about 4 days later, there are some spots that appear to have some sludgey brown crap on them.

Could it just be a buildup of nutes that got stuck to the roots, something I could pull apart and rinse out easily? Or is this definitely root rot? If so,
I've been keeping the res cooled with frozen bottles and such, and I was hoping Hygrozyme would prevent such problems, not initiate them.

Any help would be appreciated.

Side question: does it hurt the roots to have a frozen bottle floating right up against them?

Anyone? Anyone at all?

So, not that anyone cares, but I decided to give them a little H202 bath, and just kinda swished the roots around in it for a minute, and most of that crap fell right off. Though it doesn't appear to be going away entirely, it did make them look way better for a little while.
I gotta say, I like the hydro speed, but I effing hate the delicate nature of the thing. I think soil is in my future.

Thats not root rot. Thats that FF nutrients. Mines were the same way and they grew to be some BEAST!!! Your plant looks healthy so grow on brother!!

Right on dude Thanks for the reassurance.

If/when you get root rot. You will know. There will be slime (literal snot like slime) on the roots and they will smell bad. What you have is pretty typical root staining from the nutrients.

its your water! do you use H202? try another water next time. its okay though

Yeah, I just put some H202 for the first time to clear it out. I was using Hygrozyme, but I don't know how I feel about using both of them... esp until I get a TDS meter.