Droopy plants dark phase

[SpaceNeedle]

I changed the water yesterday - 4 gallons of water and I added 2 cups of 3% H202 in addition to the nutes. One plant looked particularly droopy after 45 mins, so I emptied out a 1.5 gallons of the nutes+H202 water and replaced it with ph balanced water without anything else.

TWO CUPS of H2O2? If nothing else, that is wrong for sure. Maybe 2 teaspoons would have been appropriate.

sn