Humidity !!!!

BigBud420.

BigBud420.

Active Member
Hi guys I dont get the whole reletive humidity Vs temperature thing so can someone guide me in this area pls. My temp stays around 68F I know it's a little low but with all my efforts this is the best I can get even with a heater on permanently guess typical UK shit weather lol that said my plants are in full veg what humidity should I be aiming for in regards to temp it's at 48% atm
 
Bose

Bose

Well-Known Member
48% RH is not bad. My concern is the temp. 68 is good when lights are off. When lights are on your temp should be around 77%. If you have a heater why not get a thermostat to plug it into and control your temps?
 
BigBud420.

BigBud420.

Active Member
Bose said:
48% RH is not bad. My concern is the temp. 68 is good when lights are off. When lights are on your temp should be around 77%. If you have a heater why not get a thermostat to plug it into and control your temps?
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Because it's on full power now :/
 
v1sual

v1sual

Well-Known Member
Vapor Pressure Deficit. So you would want to be in the orange on that graph for optimal growth. Thats the sweet spot. Although when growing cannabis you don't want your humidity to be above 60% unless you want moldy buds.
 
outlier

outlier

Well-Known Member
BigBud420. said:
OK guys thanks for your input just wanna show of my upgrade been working hard on this here's a couple pics...

Oh got my temp to 72 but humidity has dropped to 38% in doing so.
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You need to lower your temps to increase your humidity. 48% at 68f means your dew point would be about 50f. The dew point is where you hit 100% RH.
 
outlier

outlier

Well-Known Member
BigBud420. said:
So is it better to have humidity over heat ?
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Too much/little of either is not good.

Based on the graph v1sual posted, it looks like you need to drop your temps slightly to bring it into the "zone". As mentioned though, 20c and 48% RH is not too bad. A little cool and dry but that's to be expected in the UK this time of year. I personally would not worry about it unless it starts skewing further :bigjoint:

Some info on temps/RH/VPD here: http://www.growweedeasy.com/temperature

More info on VPD here (appears to be the source of the graph v1sual posted): http://www.just4growers.com/stream/temperature-humidity-and-c02/vapor-pressure-deficit-the-hidden-force-on-your-plants.aspx

Handy little dew point calculator I found: http://www.dpcalc.org/
 
BigBud420.

BigBud420.

Active Member
OK since my humidity drip I just thought to add my old humidifier just under my intake fan on the exit end humidity is now 48% and temp 68F it's been a struggle but I got there I can maybe change both if there is a more optimal range I can go for
 

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BigBud420.

BigBud420.

Active Member
OK so I got my temp to 72F and humidity at 60% but I achieved this by turning off my fan my question is now is that risky and will the 8" intake driven by a RVK fan be enough air movement with ×0 fans ?????
 
v1sual

v1sual

Well-Known Member
I usually only have just one fan running (6" inline exhaust) and I have enough air movement. I only turn on my small canopy fan when temps are getting into the 80's, to cool it down a couple degrees.
 
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