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Too much variation between temperatre and humidity


New Member
Before I started my grow I figured it be a good idea to get temp/humidity readings. My planned growbox will be outside with some shelter above it to protect from possible rain.

After recording for a few days I've gotten varying results...
(Every 12 hours I reset my monitor and record the Lowest/Highest measurement for Temp/Humidity for that 12 hour cycle)

Average LowTemperature: 60 F
Average HighTemperature: 73 F
Average LowHumidity: 52%
Average HighHumidity: 71%

What concerns me is that some days the MinHumidity will be 30% and other days 75% and the MaxHumidity will be 43% some days and 99% other days.

I was planning on buying dehumidity (silica) gels to lower the humidity, but clearly sometimes this would mean that my humidity would get too low!

How do people deal with this? Temperature is somewhat stable, I'm more worried about the humidity. Note that its a small growbox so I can't fit in a very big heater/humidifier that turns on when a thermostat tells it to.

Will I still be able to cultivate, or should I just toss my plans aside :( ?


Active Member
All these problems are solvable , once you have plants and lights in the grow room you will get different readings then you are now. As the lights add heat and plants will sweat out water at different rates as your grow, you will have a better idea on how stable your readings will be. At that point you can always add venting , humidafiers , and de humidafiers. Ac units or cooled light tubes. Every grow room will react differently and learning your system wil come in time. But remember, all problems are solvable .

indica vet

Well-Known Member
humidity fluctuates massively day to day outside in nature , if the temps are pretty consistant i wouldnt worry to much but yes maybe dehumidify if your concerned.
being outside a bigger prob for your grow box will be pests


New Member
Rock salt in a 5 gal with holes in the bottom and place that rock salt bucket inside another 5 gal. This can help lower humidity on high days. And if ur pulling air in from outside u can mist early in the day or in the evening(light cycle not actually day) to help on low humidity days . It's getting cold where I live. So to avoid temp and humidity problems I pull air from the house and filter it out into the heat ducts. Helps lower heating bill in winter. Great for basement growers. Goodwill and Salvation Army frequently has dehumidifiers and humidifiers where I live.


New Member
Lets not forget that these plants came from nature long before we walked the earth. Unless you have a strain that has been bred for indoor cultivation only, I wouldnt worry too much about temp and humidity fluctuations. Why try to fix someting that is not broken. I say push ahead with your plans and when and if a problem arrises, then lets go back to the drawing board.


New Member
Great, thanks for all the replies guys!

And indica vet thanks especcially to you for reminding me of pests, I went to the store today and bought some foggers (for before I begin) some EcoSmart pesticide (around my grow tent), and some Bayer Natria Neem oil spray (on my plants).

Blueballavngr do you think this product http://www.amazon.com/gp/product/B0029EGUNG/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1 will work just as well as rocksalt? I already ordered it and would be easier.
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