This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.


Well-Known Member
Apr 6, 2009
Reaction score
I know humidity can bring about mold during flower but can it decrease potency? My plants seem to be fine at 60% in the 8 th week of flower. No mould but how about potency?
I live in the waaay-down South and until I did my mini-split recently I didn't get below 60% RH. Your plants probably prefer the RH above 60, but unfortunately so does Botrytis.

My answer to your question is: no, I don't see any potency problems with high RH. Problem is, that high RH is usually accompanied to the dance by her ugly sister--high temps.
that high RH is usually accompanied to the dance by her ugly sister--high temps.
and not sufficient ventilation. Have you checked RH within the canopy? or just in the open air of the grow? betcha its higher in the canopy.

:rant:I hate bud rot. when ever I see even a spot or two I end up turning the
entire batch to butane honey oil. :hubba:
Do whatever you can to control your humidity, if only for the plants sake. I dont know its effect on potency but its effect on plant development can be quite dramatic.
High humidity coupled with high temps is asking for all kinds of things you dont want growing in your room, including mould and bot. If you throw in lack of ventilation and lack of air movement and you have the perfect breeding ground for all manner of nasties.

There is also the effect on carbon filters as well, above 60% their effectiveness is reduced, above 85% they dont work!

I target my rh in flower at 40% , veg is 50% give or take 10% for both.
The room is in a basement. The temps are around 75 with the lights on and I have very good circulation. I know I need a dehumidifier as soon as possible. I was just worried about the buds losing potency these last couple weeks of flower. I pulled a little off and dried it and it smoked pretty good. The taste was awful with no cure but I was high and stayed that way for a long time :)

Latest posts