fan on 24/7?

should i leave my fan on all hours,
or should i turn it off when i turn the lights off?

Probably wouldn't hurt, unless your dark period temps get low. Check the temp when the lights are off and see.

I'd keep it running 24/7. We want strong and sturdy stems.

you don't really need a fan on when the lights are off. it wouldn't make a difference one way or the other. the amount of air you want blowing on the plants isn't much. you want a gentle breeze, not a freaking hurricane.

Leave the fan on

i leave mine on 24/7 makes them nice and strong

thanks everyone

Silky Shagsalot said:

you don't really need a fan on when the lights are off. it wouldn't make a difference one way or the other. the amount of air you want blowing on the plants isn't much. you want a gentle breeze, not a freaking hurricane.

Click to expand...

Survey says?

YOU FAIL...

GrnMan said:

Survey says? YOU FAIL...

Click to expand...

LOL, uh oh ladies and gentleman, we have a heckler. sorry bud, i ain't biting! dude asked a question, i gave him an answer. if he left his fan on or off it would make no difference in the plants health or development. the reason you place a fan on plants is to give them air/co2, not toughen it's stems. a gentle breeze is all that's needed. you can actually do damage to your plants stalk by having too much wind blowing on them.

This is getting good. I had the same question.... 24/7 or just when the lights are on?

I leave my exhaust fan on with passive inlet 24/7.
My inlet and oscilating fans only come on with the lights.
But that's mainly because it's winter here and the nights are way too cold to have air blowing all night.
What Silky Shagsalot says is partly correct, but the fans do also strengthen the stems so they can hold the weight of the heads.

I have 2 wall mounted 15cm desk fans a 200mm air intake (standard blade driven fan style) and a 250mm centrifugal exhaust fan that moves 792m3 of air per hour, all running 24/7 and a dehumidifier during late flowering (I live in a humid climate), it blows air around about as much as the 15cm desk fans. Can't beat good circulation and ventilation.

Cheers.

When lights go out, humidity rises. You should leave your fan on for at least a little bit after your lights go out if you have issues with humidity. If your humidity stays pretty low, like under 40% when the lights go out, then you don't need to run your fans after they go out.

Running fans after the lights are off will aid in cooling the cab faster, and if you're having humidity problems, will help with that as well. I leave mine on 24hrs just because I had a problem with humidity once, had a nice 1/2 oz cola with mold in it. So I just run mine 24hrs to be sure I never have that problem again.

I just leave them running because plants LOVE fresh air haha. If you've got good circulation and ventilation then mold won't be a problem. And having cold night temps makes some strains turn purple (which is useful for bag appeal if you sell to idiots that know nothing about weed - coz they tend to think like; shit cuz that's some purples buds man, that shits musta be good bro) hahaha

Where I live it's very humid and at it's lowest id about 60% RH and for most the year is 80% RH (even in my cabinet), but good circulation and ventilation = no problems with mold or anything. Plus I got the dehumidifier (as mentioned earlier) for late flowering to drop that RH a bit if need be.

Some info:

During seedling and veg, it doesn't matter how high your humidity goes, in fact clones and veging plants love high RH (relative humidity).

During flowering, if your RH is 40-60% (or lower than 40%) you shouldn't have mold problems. Especially if you have a circulation fan too. Remember circulation and ventilation!

my fans run 24 hours like in the post build up some nice fat stems and growth with the fans blowing 24hrs a day cheers

Wondering the same thing...

i leave mine off. save on elec bill and to keep temps steady. i only have the fan on when the lights are on so that it blows abit of heat away from them and then they can get good air circulation.

if u want ur stems to be fatter then just roll them inbetween ur fingers gently. do this a couple times a day for a few days and ur stems are nice an strong! no need for the fan to be on to fattern ur stems.

as its been said thou, u only really want a fan so that the co2 around the plant can move about otherwise the plant is gonna use all the co2 around the leaf in about 20mins. so keep the circulation up.

Silky Shagsalot said:

LOL, uh oh ladies and gentleman, we have a heckler. sorry bud, i ain't biting! dude asked a question, i gave him an answer. if he left his fan on or off it would make no difference in the plants health or development. the reason you place a fan on plants is to give them air/co2, not toughen it's stems. a gentle breeze is all that's needed. you can actually do damage to your plants stalk by having too much wind blowing on them.

Click to expand...

Wrong again. Using a fan doesn't give them C02 unless you have it pulling air from outside - a C02 setup does that. Leaving the fan running DOES promote healthy strong stems. In nature, you would have the wind blowing on your plants which would do the same. Having a fan running also helps with moving air around and keeping humidity levels stable which also helps keep mold away.

GrnMan said:

Wrong again. Using a fan doesn't give them C02 unless you have it pulling air from outside - a C02 setup does that. Leaving the fan running DOES promote healthy strong stems. In nature, you would have the wind blowing on your plants which would do the same. Having a fan running also helps with moving air around and keeping humidity levels stable which also helps keep mold away.

Click to expand...

co2 is in the air, everywhere. when plants get thick and bushy, co2 gets scarce inside the leaves/branches. fans exchange the air inside the plants leaves/branches, which supplies co2. in nature, as you mention, the wind isn't always blowing now is it? as a matter of fact, days could pass without any wind. yet these plants, and their weak stems, (LOL) survive. humidity levels are controlled by dehuey's/humidifiers, not fans. if you have access to fresh air then there's need to buy expensive co2 equipment. unless your room is sealed, a co2 system is pretty much a waste. i doubt if many here have sealed rooms.

Silky Shagsalot said:

co2 is in the air, everywhere. when plants get thick and bushy, co2 gets scarce inside the leaves/branches. fans exchange the air inside the plants leaves/branches, which supplies co2. in nature, as you mention, the wind isn't always blowing now is it? as a matter of fact, days could pass without any wind. yet these plants, and their weak stems, (LOL) survive. humidity levels are controlled by dehuey's/humidifiers, not fans. if you have access to fresh air then there's need to buy expensive co2 equipment. unless your room is sealed, a co2 system is pretty much a waste. i doubt if many here have sealed rooms.

Click to expand...

Co2 is not waste by any means!! The natural air has about 300ppm of Co2, but plants grow best at about 1500ppm of Co2. So raising the ppm by 1200ppm will have a great affect on them.
You don't need a sealed room, you just need to turn off your exhaust fans while your plants are in their Co2 enriched environment. A 20min session 10 times a day will cause a tremendous amount of growth.
Also, the wind is always blowing. It may not be large gusts blowing down trees, but air is always moving. If wind wasn't always blowing, we wouldn't have particles in the air because they would settle to the ground. Yet we have tons of shit in the air. Why? Because the air is always moving.

Also, Green Pheonix, if temps get too low, the plant doesn't grow as well. You don't want your temps to dip much more than 10degrees from the day time temps. Sure purple looks cool, but wouldn't you rather have much better bud that's not purple?