@bubbles yes, I've had some of that whitish mold stuff frequently on my plants in the 6 x 8 Harbor Freight GH - (not on the GH itself). But
@Drdawg mentioned I needed to run fans at least 8 hours a day and that has helped substantially. Also, someone posted the info about using peroxide (the 3% from the store is mixed 1 tablespoon to a cup of water) and spritzing the soil with that. That has cleared it right up. I didn't put it anywhere on the GH itself though, cause I don't have a problem there.
Interesting that the little popup GH on the patio (bought from Amazon for $100) hasn't had much of a mold problem at all. It gets lots more sun, so I don't know if that impacts it.
Yes, gullywasher - we've had over 1.5 inches of rain here in Gtown just overnight and still drizzling. Happy to see it though ... it can keep coming and fill up Lake Travis