I'm confused about humidity

I was running my new seedlings in the 30 to 40% rh range and 76F to 81F. I bought a humidifier and now it’s about 60-70% rh range.
I was told to ditch the humidifier due to possible powdery mildew.
I don’t know now.
I only plan on using it during low humidity weather and NOT during flowering.
I think I’ll be fine…what say you?

I agree, as long as you are keeping your humidity at the proper levels for the stage of growth, you’ll probably be fine.

If you keep a schedule something like this you should do fine:

Growth Week 1: 60%
Growth Week 2: 60%
Flowering Week 1: 55%
Flowering Week 2: 50%
Flowering Week 3: 50%
Flowering Week 4: 50%
Flowering Week 5: 50%
Flowering Week 6: 45%
Flowering Week 7: 45%
Flowering Week 8: 40%
Flowering Week 9: 40%

The main concern with a cool mist humidifier like this, is mold and mildew growing in the humidifier and then the spores being distributed in the room. This is why some people prefer the “hot” humidifiers instead of the “cool” atomizing or sonic humidifiers, as the hot ones kind of boil the water as is creates its mist or steam, killing any mold, mildew or fungi spores. However, a good regular cleaning regiment of the humidifier and maybe adding a little H2O2 or maybe even a tiny bit of bleach, and this will also make sure these things won’t grow in your humidifier.

Happy growing,


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OK so you have good airflow leaves are not visibly wet and mildew is a concern in your controlled well spaced environment? First let me say your seedlings and veg cycle will love you for the added moisture and a clean well vented tent is easily controlled environment. Mildew is mostly an issue with little air movement constantly moist wet leaves or tightly packed plants and buds :wink:
This is a matter of what you feel you can safely control. Relax take a breath and think what do my plants like and want for a happy if somewhat short life?

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Thanks for the cleaning tip. It’s brand new but I’ll disinfect it now and then.

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Thanks for the reassurance!!

It’s gone get real crowded in there now that them babies have cool humid air , which relatively is a great thing in veg , get ready get ready , what MacG posted is exactly what you want to aim for , no more no less , MacG is a Chemistry , biology major !!!

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