Mold! Recommendations what to do about it?

I was watering my plants today (which are still vegging, about three weeks old now), and I saw a little bit of white powderey substance at the base of the stem, spreading to the edge of the Rockwell cube she's growing in.

Any recommendations what I can do? I'm not too worried, because it doesn't look like it had spread to any of the other plants yet, but obviously I want to get rid of it before it becomes a bigger problem

I really appreciate any advice!

Spray with Safer Fungicidal Soap. Should take care of it. Also, feel free to spray the rest of your plant with it too, just keep it out of intense light after spraying. The less you spray near the root zone the better though. There's also a product called Actinovate out there that will take care of it too, both as a foliar spray or root drench. In both cases, use 1/2 teaspoon per gallon.

Thank you--most of the mold is sitting at thte base of the plant (on top of the Rockwell), so starting with the treatment that is safer for the roots is probably the best idea.

(Is it safe to pre-treat weekly with these products, or is it better to just use when mold is atually there?)

I appreciate that you got back to me The mold just started, so hopefully this will get rid of it before it becomes a bigger problem...

If you're using the Actinovate product, you can apply that directly to the nutrient solution, but as for the Safer Soap fungicide, only apply minimally as possible needed near the root zone.