But
High humidity kills charcoal odor scrubbers fast.
mold loves it humid.
indica often come from dry arid areas.
I never had a humid grow, sativas do ok for me in 10-15% RH.
wonder if it would help them......
i didn't know that about charcoal filters... i don't use mine! so perhaps those that use them might need to take that into consideration, but for those of us that don't use them, it's a non-issue.
as for the mold, get a Hepa filter. humidity doesn't cause mold; mold spores cause mold. True Hepa filters down to something like .2 micron, and that will prevent mold spores from coming in with the intake air. i use a DustShroom, and it works perfectly, even without having been cleaned in over a year!
i haven't used a dehu in a grow room for a long time... what i noticed within a week when i made the adjustment to adhere to the proper VPD, was that the plants didn't dry their soil as quickly, and also they had less likelihood for leaf tip burn; overall they looked a lot healthier. dryer air draws moisture from the plant at a higher rate (increases evapotranspiration), which causes an increase in the uptake of water by the roots. as the water moves into the plant, osmosis carries additional nutrient ions into the plant too. these excess ions can contribute to burn. dryer air is like force feeding the plant, higher humidity in proper accordance with VPD will allow the plant to eat at a more leisurely rate, as it wants to. just remember to use a Hepa filter. and with that Hepa intake, keep the room at a positive pressure, to ensure that any air leaks in the room are not entry points for spores, bugs or other pathogens/vectors.