I am planting a few clones tonight. Before I plant one of the first things I do is disinfect my pots w/ hydrogen peroxide. It's better than using bleach, does the same trick (kills mold). I scrub them to get any old calcium deposits off . I use 1/4 cup per 1 gallon of water. I am using a couple of clay pots and those need to be soaked for at least an hour in clear water. This prevents the clay from sucking all the water up from the soil.