root rot? sick plant? droopy leaves? help me fix this please!

Alright. So my plant (ch9 vintage 2006) was growing wonderfully then we got into some oddly warm weather while I was away at work and came home to a wilted little girl. Water smelled bad. Changed the res and flushed with clean water for a couple hours while I sprayed away what seemed to be some slime. Cleaned and boiled my airstones and cleaned my bucket really good as well. Water hasn't spiked and I haven't seen the slime come back either.
I mixed a 2.5/5 ratio of micro and bloom into a 5 gallon bucket and ph'd it and added that back into the res after all the cleaning. My ppm currently is 473 145 of that being from the ph'd tap water so nutrients are around an actual 328. The roots are a little brown with new white growth coming in as well it looks like from the pictures. Any advice is greatly appreciated. Just hope I caught it in time. Ambient temp is currently 76. The thermometer is right by the heater as well. And i'll be turning that lower once the hps comes on in a bit. Water is also ph'd to 5.5-5.7 depending on how much I move the pen and all. Just hoping I can get some input on the situation as well as how to prevent it besides the obvious.
Also. Does light penetration cause root rot? I can catch some of the water bubbling under the hydroton out of the corner of my eye sometimes but the plant is growing too low to pull it up and fill in around it. Or could I? I've also added my h202 than usual to try and prevent the same thing from happening. Pictures are included.
Help me out please!

It sounds like everything should rebound fine. H202 should help clear up and further prevent root rot. If your temps are back to normal and plan on staying there, then no problems right? Hydro is nice like that, if you catch a problem in early stages, IMO its easier to correct. What is your water temp?

That's the thing. I'm smart enough to buy a ph and ppm pen. But absent minded enough to go down the road and buy a cheap wal mart themometer haha! I'll grab one tomorrow at the store. It feels..cool? I mean I can tell that it's below room temps and shouldn't be hot enough to cause rot. Do you think that's what happened to this plant? The roots look slightly brown but could that be from nute stain as well? I do know there was something growing on it and since last night it seems it hasn't been back. I just basically sprayed the piss out of the roots and got the gunk off as well as doing a thorough cleaning. I just really want this one to survive. I dropped it on it's head as a sprout. Stressed it with heat AND burned it with nutes. All to have an awesome recovery and now this! haha this is what it used to be.

I'll be growing 24 plants of this strains outdoors this summer. I'll start the thread for setup sometime in the next few months. I'll be following this though, definitely get a new thermometer. I like the digital one, for 5 bucks on ebay, which is also a humidity meter and tells the time. I agree with budbuddysmile, should rebound perfeclty fine. Goodluck keep posting pictures. I'm also doing CH9 jack, Pow 33, B.l.t, Green Bud + 5 other strains.