were you reading smoke2live420, don't use the 3% it has a additive that will hurt your plants, use 2 drops of 35% h2o2 for every gallon, and let sit for 20 minutes before adding nutriensts, you can get h2o2 from a nursery or grow store, it is cheap and lasts forever. If you use to much or don't let it sit the high o2 concentration of you water could kill the beneficial microbes in your nutrients or soil. However because of the oxidizing effect it is the best thing to use when sterilizing equipment, just use higher concentration for cleaning.