Overwater or something else?

It’s my first grow and have these two in a DWC, 25 days in.

Everything was going well until a day after my res change(9/6). Changed res 9/6, 9/7 still looked OK. Morning of 9/8 became very droopy. Changes from previous was maybe a little extra water. I also turned off my top feed on the 9/7 as the roots had reached the water.

Res was initially filled with 10 gals but got a bit overfilled so maybe the two air pumps weren’t enough or too high to the net pots. Roots look dark but think it’s the nutes as they aren’t slimy and no smell. I’ve changed the res again on 9/8 and lowered water to 9 gals to allow 1.5 inches of space between net pots. Would you agree it’s likely overwater and not enough oxygen? Wasn’t sure if it would change overnight like that. Any idea how long to take to bounce back or any other fixes to try?

PPM currently at 550, ph around 6. Turned back on the top feed to move around the water a bit more and still have the 2 air pumps going with 9gals.

Pictures of how they look now, roots, and how they looked 9/7.

You might try to wash those roots in some peroxide and water.

Water temp should be in the low 70's. Could throw a frozen bottle of water in the rez until you get a chiller. Your shorter roots look cleaner than the longer ones. Looks like some kind of root rot. Do you have any beneficial bacteria in the rez? I would clean those roots with peroxide and water bath first thing. Just for a couple of minutes, until the roots look lighter.

Thanks. I do have hydroguard in there. Water is temping at right at 70. Good note about the frozen water bottle.

Any process to bathe in the water peroxide and then get back into the beneficial bacteria water? Soak roots in mixture, rinse with water, back in rez? Want to make sure I don’t mess up the beneficial bacteria with the peroxide.

Yeah, I just get a bucket and put in a tablespoon of peroxide to a gallon of water soak the roots for a few minutes watch the bubbles do their magic, rinse with tap water. I let it dry for a few minutes and then put it back in the rez. If your rez is dirty, dump the rez and I'd give that a good cleaning with bleach or peroxide and replace the water and nutes.