ways to bring humidity down

SkunkGuy

Active Member
hi all just woundering if there any handy way to reduce humdity in a grow tent as its keeping up around 70% mark and not cuming down ?? i have a 5" plus carbon filter and 4" blowing air in and 2 fans blowing inside

can i use my fan blowing as a exchaust aswell
 

ChoofyN

Active Member
No need to spend big bucks, if you're in a tent, 2 fans is all you need, 1 exhaust and 1 intake, generally most have a higher intake to create a positive pressure inside the tent (pushing unused air out any holes or wherever it can get out). this proper ventilation method will reduce humidity and you won't need to have the 2 fans inside the tent, as the positive pressure inside creates enough air movement to give a gentle breeze all over your tent which is a lot better then running 2 fans.
 

SkunkGuy

Active Member
No need to spend big bucks, if you're in a tent, 2 fans is all you need, 1 exhaust and 1 intake, generally most have a higher intake to create a positive pressure inside the tent (pushing unused air out any holes or wherever it can get out). this proper ventilation method will reduce humidity and you won't need to have the 2 fans inside the tent, as the positive pressure inside creates enough air movement to give a gentle breeze all over your tent which is a lot better then running 2 fans.
hi thanks for that but al the above i have in my tent i have a 1.2x1.2x2.0 tent 400watt hps system 5" exchuast and 4" inline and 2x clip on fans inside and my hum has not changed since i switched over to hps over a week ago
 

hengus

Member
Sand - spread an inch or two across the bottom of the growing area, should take about 20 or 30% out f you replace it regularly - the best stuff is playsand for kids, although any kiln dried should do, make sure you replace it every week and watch your temperatures. Another option would be perlite although it's a bit more pricey...

Good luck :0)
 

tyke1973

Well-Known Member
Make sure that your out take fan is larger than your intake,and all should be fine.I use a 9" fan out take for 2 x 600 hps,and a 6 " for my in take.If you use a decent set of fans like above and couple this with two ossalating fans then this will normaly keep the humidity in check.
 

SkunkGuy

Active Member
Sand - spread an inch or two across the bottom of the growing area, should take about 20 or 30% out f you replace it regularly - the best stuff is playsand for kids, although any kiln dried should do, make sure you replace it every week and watch your temperatures. Another option would be perlite although it's a bit more pricey...

Good luck :0)
thanks for that im going to try this now take out all my plants and put a layer of sand into my tent cheers again +1 rep

Make sure that your out take fan is larger than your intake,and all should be fine.I use a 9" fan out take for 2 x 600 hps,and a 6 " for my in take.If you use a decent set of fans like above and couple this with two ossalating fans then this will normaly keep the humidity in check.
hi there thanks my fans im using as i said are 5" out with 280m3/h and my in 4" with 187m3/h and i also have 2 fans i also after thinking that i cut out a piece of carpet for under my tent as there was alot of viberation on the wooden floor in my house so taught about carpet would this be the cause of my problem as it could be soaking up all water after feeding and not drying up propley
 

Illegal Smile

Well-Known Member
If the air you bring in is no dryer than the 70% air, it won't bring humidity down much. You might try rigging up a way to take air coming directly out of a dehumidifier into the tent. On the other hand, you might consider just living with 70% - the main implication is that you will have to be very careful in the drying and curing process.
 

nick17gar

Well-Known Member
well 70% is pretty high. unless your in a very tropical climate, chances are thats higher than outside. do you have water sitting around anywhere? perhaps tap water your letting sit for a few days before using? a fish tank nearby with some pretty goldfish? any standing water (with a little heat) with raise humidity. what kind of grow are you doing? if your in soil, this is very odd. if your doing hydro, you can lower the humidity by making sure everything that contains water is covered (so the light doesnt help evaporate water as quickly).

Personally, relative humidity here where i live is high. 70-99%. every day. every fucking day. the only reason my plants are at a steady 40-50% humidity is the AC unit, which makes me about 10 gallons of water daily (which i use to feed right back into the plants).
 

SkunkGuy

Active Member
thanks i went and got something like this and put it in earlier and before i put it in it was still at 70% and just before lights out at 4 it was at 63% so its doing its job see what the morning brings
 

TwistedSoul

Active Member
try a damp rid... not sure how your Humidity is staying so high in a tent with a HPS light in it, unless you have abundance of water in your tent.
 

hengus

Member
another cheap alternative is Bicarbonate of soda... and the good thing is that as it gets damp it releases a little CO2. Which is nice. If you're a little plant.
 

inhale112

Member
I have the same problem in my 60x60x120 tent my out blowing fan is bigger then my intake fan. i have a 400w hps so during the days i have no problem its around 40-50% but at nights it goes up to 65-70% and i don't have room for any dehumidifier. is it OK whit a bit higher at nights or do i really need to fix it? and sorry for stealing an old thread ;D
View attachment 2682608
 

kryptoniteglo

Well-Known Member
I have the same problem in my 60x60x120 tent my out blowing fan is bigger then my intake fan. i have a 400w hps so during the days i have no problem its around 40-50% but at nights it goes up to 65-70% and i don't have room for any dehumidifier. is it OK whit a bit higher at nights or do i really need to fix it? and sorry for stealing an old thread ;D
View attachment 2682608
I have a similar size set up to you -- when my plants were in flowering and the tent was closed, the humidity rose to 90%. Once the buds started getting sizable, I realized this could create a serious mold problem. I did buy a dehumidifier, which I ran inside the tent the first night, only to discover it jacked up the temperature too high. But I needed it. So I would open the tent from the bottom, position the dehumidifier on the edge of the tent so that it pulled in moist air from the tent but released its operating heat into the room. I then taped the tent around the dehumidifier and packed any holes with towels to fix light leaks the best I could. A pain for sure, but better than getting mold!
 

inhale112

Member
I have a similar size set up to you -- when my plants were in flowering and the tent was closed, the humidity rose to 90%. Once the buds started getting sizable, I realized this could create a serious mold problem. I did buy a dehumidifier, which I ran inside the tent the first night, only to discover it jacked up the temperature too high. But I needed it. So I would open the tent from the bottom, position the dehumidifier on the edge of the tent so that it pulled in moist air from the tent but released its operating heat into the room. I then taped the tent around the dehumidifier and packed any holes with towels to fix light leaks the best I could. A pain for sure, but better than getting mold!
lol thx for the fast answer, dam i have to get out and get a dehumidifier! i rly don't want mold
 

Sunbiz1

Well-Known Member
lol thx for the fast answer, dam i have to get out and get a dehumidifier! i rly don't want mold
I use a de-humidifier for seed storage, they use quite a bit of electricity. Another poster already mentioned baking soda, I'd try using an entire box spread out on a paper plate etc. first. You might just find it to be a much cheaper alternative.
 

Greenean

New Member
hi all just woundering if there any handy way to reduce humdity in a grow tent as its keeping up around 70% mark and not cuming down ?? i have a 5" plus carbon filter and 4" blowing air in and 2 fans blowing inside

can i use my fan blowing as a exchaust aswell

Humidity is a BIG problem whilst plants are flowering, but is great for them when they're vegging
Try getting a more powerful fan, there are two types:-
A1 - lower air flow,
L1 - higher air flow,
L1, although more expensive, is what you need if your having problems with humidity, make sure you find out how much air it moves as wewell also, if you're growing in soil, try taking your pots out of the tent to water, let them drain, then put them back in, anywhere between 40-70% of water is run off (depending on your medium), and water sitting in the bottom of a tent evaporates quickly under a 600w hps
 
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