Quest dehuey. Done.
Humidity too high
- Thread starter Bloom SA
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~star~crash~
Active member
lights out i cant get my flower room down below 55% ...they seem happy & got some fat buds in there..(fingers crossed) ... lot of air movement above and below the canopy ...lots of defoliation ...
Thanks for the advice brother. I am old guerrilla who's finally looking at coming out of the bush. Its nice to know others have experience in growing in this type of environmental conditions.
You would still have to deal with the humidity, maybe it would be better being stable temps because of the ground.
Theoretically it could be less electricity in a greenhouse because of not having to run lights year round, but that would depend on how you equip the greenhouse, and use it
If your electricity is cheap, it may be somewhat close, depending on equipment used, lights, heat, fans,, cooling.
If you think reducing the rate of transpiration of the plants will help, apart from the aspirin, you could try pushing your nutrients/feeding up, gradually till your plant are taking the maximum they can without toxicity. Plants only transpire in order to siphon up fresh nutrient rich water at the roots. If they are well fed they will transpire a lot less than if they are hungry. If they are hungry they will endlessly cycle more water through themselves, from roots to stomata, in search of nutrients.
If you have high humidity where you are, period, its a tough one.
If you have high humidity where you are, period, its a tough one.
Something else to consider
Something else to consider
When running bigger bud producing strains where mold/mildew is a real concern we run regalia. It works very well and is nice since it's not a foliar, you just feed it so it can be run later into flower. It's worth a read.
Something else to consider
When running bigger bud producing strains where mold/mildew is a real concern we run regalia. It works very well and is nice since it's not a foliar, you just feed it so it can be run later into flower. It's worth a read.
~star~crash~
Active member
start crash
sounds like very sound advice.Whats your climate like ?
i'm in the North East it's winter ...if thats what ur asking
I used to grow greenhouse hydro tomatoes and we used propane forced hot air heaters for both temp temp and humidity control. No dehumidifiers.
Exactly thanks.
I agree. Working off of a basic VPD table, I'd use a heater to crank up the heat up to 25c, and have the RH% between 75% and 50% - depending on the growth stage of the plants in the green house.
I agree. Working off of a basic VPD table, I'd use a heater to crank up the heat up to 25c, and have the RH% between 75% and 50% - depending on the growth stage of the plants in the green house.
I have propane heat in my greenhouse. It is about 20% humidity here all summer during the day, spikes higher at night but still stays at 60-70% humidity which is fine.
Problem comes after first rain in the fall, night humidity levels hit 80-90% at night. Propane isn’t enough for me to lower my humidity at that point so I either continually run vents or dehumidify.
Problem comes after first rain in the fall, night humidity levels hit 80-90% at night. Propane isn’t enough for me to lower my humidity at that point so I either continually run vents or dehumidify.
CrushnYuba
Well-known member
If you want to check out my greenhouse thread, i explain dehumidifying with heat in detail. I personally use pellet heat but any heat can be used as long as if it's fuel burning, it's vented.
Meaning of you are using propane or NG it is a vented unit. If it's not vented you are just adding more moisture.
Dehumidifiers are hardly ever more effective then heat dehumidification. The only time that heat dehumidification is not an option is when it's hot and humid. And the rise in temperature needed to dehumidify would put you over 90f. In that case you would want to use an ac unit to dehumidify.
That said, if you are relying on electric heat, you might as well use a dehu to create that heat as 1kw of electricity creats 1kw of heat regardless if its a 1kw space heater, 1kw dehu, or 1kw blender or toaster oven.
For every 20 degree rise in temperature humidity is cut in half.
So say it's 80%rh and 60f out. If you bring that air into the greenhouse and heat it to 80f, you now have 40% humidity in your greenhouse.
If you have good horizontal air movement, you shouldn't have problems if rh stays under 70% or so. And you shouldn't have problems if your temps stay below 90f or so.
Meaning of you are using propane or NG it is a vented unit. If it's not vented you are just adding more moisture.
Dehumidifiers are hardly ever more effective then heat dehumidification. The only time that heat dehumidification is not an option is when it's hot and humid. And the rise in temperature needed to dehumidify would put you over 90f. In that case you would want to use an ac unit to dehumidify.
That said, if you are relying on electric heat, you might as well use a dehu to create that heat as 1kw of electricity creats 1kw of heat regardless if its a 1kw space heater, 1kw dehu, or 1kw blender or toaster oven.
For every 20 degree rise in temperature humidity is cut in half.
So say it's 80%rh and 60f out. If you bring that air into the greenhouse and heat it to 80f, you now have 40% humidity in your greenhouse.
If you have good horizontal air movement, you shouldn't have problems if rh stays under 70% or so. And you shouldn't have problems if your temps stay below 90f or so.
I am learning so much from this thread. Thanks Redlaser for the info.
What is the size of your greenhouse ?
What heater are you using ?
Do you have an idea of monthly fuel cost?
I am only planing on a summer grow looking for small plant count larger weight/plant.
CrushnYuba
As someone new to the GH forum I have seen your posts a few times now . Can you provide a link to your GH thread?
CrushnYuba
Well-known member
CrushnYuba
As someone new to the GH forum I have seen your posts a few times now . Can you provide a link to your GH thread?
https://www.icmag.com/ic/showthread.php?t=339175
Most of the pictures were lost. I need to run around and take replacements.
reading your thread and your post in this one have been hugely inspirational while i get ready to put up my first greenhouse. here in maine we can have pretty insane humidity. luckily it stays cool enough even through summer that heat is almost always an option. one thing i cant get through my head however is how to pair the heat with intake/exhaust. if you are pulling too much cool and moist air in from outside, wont you defeat all the work the heat is doing for the RH%? I'm guessing its all about using something like half as much CFM coming in as going out? or maybe just run exhaust?
