Re: Quest for 1g/w: 1k hps liquid cooled on a 6' mover in a 4x8 tent.
by 3% solution you mean straight peroxide out of the bottle (if it says 3% on the bottle)? that seems strong to me. wont do any damage to the roots?
IDK about
any. Once back in the day I had a pretty substantial algae buildup at the root zone. Had two plants per reservoir growing (in pots) right through the lids. Roots were tangled so I could not easily remove the plants from the lids. I carried each reservoir lid to the kitchen, removed all the green I could from the bottom of the lid, and then adjusted my water until it felt like it was at a neutral temperature, and hosed the works pretty good. Then I realized that I had sat all four reservoir lids down in non-pristine places, meaning that all the roots were in need of another shower. This they got (one lid at a time this time). I then decided that the roots had had "a pretty hard day" and decided to give them a good soaking low-pressure drench with H2O2 from a spray bottle. While doing so I used my fingers to comb through the roots looking for any contaminates. The H2O2 ended up being 3% so yeah the same strength as consumer-grade peroxide. And I lightly shook off the roots afterwards so any residual amount would have been diluted as soon as the plants went back into their (clean & freshly-changed) reservoirs.
The plants pretty much didn't do anything for about 24 hours, then went back to growing without noticeable affect. After that, if I thought there might have been root issues, I did the same thing. I'm sure it was somewhat stressful overall (so many things are) but I attributed it to the general shock of having the roots out of solution, laying on the counter, etc. much more so than the actual H2O2 application.
YMMV of course. If the roots are thin, spindly, and brittle then I could see possible further damage occurring - mainly from the strong spray of room-temperature water.
Could I suppose damage/kill any symbiotic life in the root zone, but being (generally, more-or-less) a chemical guy, I usually fed them "predigested food" anyway and did not require additional organisms to break down the nutrients.
If in doubt, you could always treat one plant and stick it in a simple DWC for a day or two to see whether the sludge comes back and how the roots feel about it. In the summer heat I'd only run DWC for fear of inadequate O2 levels at the root-zone. At any time the "flow" was cut off I'd immediately start worrying when temperatures were unfriendly. With DWC it was never cut off. When I asked the girls how they felt about millions (exaggeration) of tiny bubbles flowing upwards through their roots and constant mixing/oxygenating from the power head, the plants said, "Mmm... Tickles." I cannot but feel that an aero setup that cycles is less efficient for getting DO to the roots than a good DWC setup because the moment that the "fog" stops, the O2 levels of the solution remnant film that is coating the roots can only drop. Especially since the amounts of O2 that we like to make available are in the super-saturated range (more O2 than the solution would normally be able to hold dissolved at any given temperature).
Or I'd get lazy and go with a soil(sic) type medium because I get pretty lazy when it's hot. But that's like looking at a bunch of time-lapse photos instead of watching the video, lol.
Just rambling
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BtW, I'd expect to see pH taking nose-dives from the looks of things but realize that you have the pH controller setup. Does that have any kind of monitoring/logging function so you can see if the pH had to be adjusted much more than usual lately?
now thats goingot be one hell of a site. 
