My flowering room rarely gets above 35% RH, and sometimes gets below my hygrometer's ability to register, so it reads --. The buds look ok to me so far. According to Robert Clarke in "Marijuana Botany," An arid atmosphere stimulates trichome development and therefor THC production. He's careful to point out that this applies to the atmosphere, not the soil. I highly recommend this book, by the way. In any event, I'd trade low RH for moldy buds any day.