Currently growing in a DWC system, have my main plant in my grow tent and clones in my closet. Currently have clones in tap water with 2mL of GROW, soaked rockwool for 5 hours. Also have humidifier in closet to increase humidity to 70-75%. Clones just don't seem to take and rockwool for one of them dries in an hour or two all the time. Main plant is in grow room which ranges from 65-80% humidity and Temps are generally 70-77 degrees. She's in about week 8 of veg, currently have her on 7mL of Grow and 3mL of Micro/Bloom. Seeing some slight discoloration (some leaves turning lime green) and have been using distilled water with a touch of pH down. I'll post pictures below, any responses are valuable.
Those humidity numbers are much higher than what I shoot for. 50% is normally ideal and encourages roots to seek water higher than that and Roots suffer because water is drawn through the leaves with high humidity. Sent from my SAMSUNG-SM-G900A using Tapatalk
You may want to cover that rock rockwool with hydroton or paper plates. anything to keep the light from growing mold on your rockwool. Sent from my SAMSUNG-SM-G900A using Tapatalk
Put them in a tray under a propagation dome until roots are growing out of the rockwool first. They are like $15 or less. That will keep them from drying out and will keep the new root buds moist. Squirt a little water on them every day or so but don't over do it.
Another suggestion. With DWC/RDWC it's not a matter of IF you'll have a leak or spill, but when. Having it right there on your carpet is tempting fate... I know all too well after flooding and destroying my finished basement - Almost done rebuilding now. Plan for the worst scenario - for real. If you are growing DWC in an area of the house that can not handle complete rez volume spill - then you really should plan some sort of containment system for a fail safe.
It's the opposite. The higher the humidity, the less evaporation can take place, because the air has a lot of water in it already, and the slower the transpiration and slower uptake through the roots. Below 30 or so and the stomata close to retain from LOSING moisture. But you're correct that 50% is good. It's ok for high humidity for clones though, which is why a lot of people use propagation domes. They have vents in the top so they don't get TOO humid. Those clones have no roots to take up water, so you want to help that water stay in the leaves. It's using that water, and cannibalizing it's sugars to make those new roots. So, keep it moist and keep the leaves from dry air.