Adding hydrogen peroxide to your water should not be done except to treat for cobweb mold
Misting with H2O2 should only be used as a treatment for cobweb mold, not as an everyday thing as a prevention method. Even though the peroxide doesn't kill the mycelium outright it does damage and weaken it.
If you do get cobweb, spray with a 3 eroxide solution (most store bought preparations are already 3 read the label on the bottle) then fan to dry it out completely. Follow with a plain water mist and another fan to dry out the surface.