Too much air pressure?

lucasnooker

lucasnooker

Well-Known Member
Hi there forum,

I have had problems before with my plants in the last couple of weeks with mold and such so i decided to go ahead and get an intake fan to hopefully stop this from happening. but I think there is too much pressure and my tent is inflating...

This is bad right? Should i just turn it off and make due with what I had already? I forgot to open the air vent last time also but i am not sure if this will be sufficient enough air flow as i have the plants quite crowded in a scrog setup but only 1 600w light so it might be ok?

Let me know your thoughts on the situation and if i should turn off the intake fan... Thanks...
 
lucasnooker

lucasnooker

Well-Known Member
Quick google search soon justified my thoughts lol. turned the intake fan off. wasted a bit of money but was only a cheap one anyways... xD i hope the air vent will be sufficient enough. do you think it will?.... thanks
 
lucasnooker

lucasnooker

Well-Known Member
Wilderb said:
Yes. Does you tent have more than one passive inlet?
Click to expand...

No. Just 1 large intake vent made of a mesh like material. It was covered up for the entirety of the last grow and i got mold because of it. So I have undone the Velcro that was holding it down and taped it up so its always open. There is also another hole for ducting for putting in an intake fan which i did but it was too much and inflated the tent. So I just opened this hole up too so there is a bit more intake air going in. Will this be enough to prevent mold? The tent is pretty packed as its a scrog, all the leaves are covering each other and theres not really any free space. I am hoping there is enough passive air to prevent bad conditions. At least its not as cold now, last time it was in the winter in very cold conditions but the weather is getting a little better now in these months. It wasn't a problem when the light was on ofc but in the cold dark environment is where the problems started i think
 
Wilderb

Wilderb

Well-Known Member
Are you using a charcoal filter? Make sure the filter is located opposite your intake. That way you will get decent air movement.
How many CFM is your fan? Are you using a cooled light?
Also something to keep in mind. Some guys use a furnace filter to help keep bugs out. Just tape it over your passive intake.
Do you leave fan running during lights out?
 
Jaybodankly

Jaybodankly

Well-Known Member
Try a powered exhaust fan and passive intake 2x the size of exhaust. So a 6" exhaust fan would need to 2-6" intake ports (lightproofed). Do you have a temp/humidity meter?
 
lucasnooker

lucasnooker

Well-Known Member
Wilderb said:
Are you using a charcoal filter? Make sure the filter is located opposite your intake. That way you will get decent air movement.
How many CFM is your fan? Are you using a cooled light?
Also something to keep in mind. Some guys use a furnace filter to help keep bugs out. Just tape it over your passive intake.
Do you leave fan running during lights out?
Click to expand...

Yes I have a charcoal filter. it has had some use though and it could be dead by this point for all i know xD I have done around 5 grows or so with this same setup and it wasn't a problem until my previous grow when i moved to a different location. The tent is now in an outhouse kind of place so its very much effected by what the weather is like outside. Temps are around 17C at night which is ok now but in the winter it can get as low as 12 at night, its really bad xD. I don't use a cooled light. the heat is a welcome bonus in such conditions of course... but yeah the intake vents are on the left front and middle of the tent and the out take is hooked up to the back right corner. It's a 5 inch RVK outlet fan i believe, tried putting in a cheap 4 inch intake fan but got inflation as previously mentioned. Usually the grow is good all the way through until the last couple of weeks but I am getting to that point now which is why i am concerned. I haven't got any mold yet but i start week 7 of flower tomorrow so this is around the point when problems can occur. But I am hoping now with the vents open that all will be well? I guess time will tell... lol and yes the outlet fan is running 24/7 :P
 
Wilderb

Wilderb

Well-Known Member
lucasnooker said:
Yes I have a charcoal filter. it has had some use though and it could be dead by this point for all i know xD I have done around 5 grows or so with this same setup and it wasn't a problem until my previous grow when i moved to a different location. The tent is now in an outhouse kind of place so its very much effected by what the weather is like outside. Temps are around 17C at night which is ok now but in the winter it can get as low as 12 at night, its really bad xD. I don't use a cooled light. the heat is a welcome bonus in such conditions of course... but yeah the intake vents are on the left front and middle of the tent and the out take is hooked up to the back right corner. It's a 5 inch RVK outlet fan i believe, tried putting in a cheap 4 inch intake fan but got inflation as previously mentioned. Usually the grow is good all the way through until the last couple of weeks but I am getting to that point now which is why i am concerned. I haven't got any mold yet but i start week 7 of flower tomorrow so this is around the point when problems can occur. But I am hoping now with the vents open that all will be well? I guess time will tell... lol and yes the outlet fan is running 24/7 :P
Click to expand...
There is no need to run fan during lights out. I use cloth pots and run a moist mix, so I have my fan set to run every 1 1/2 hours just to keep humidity down. Timers are a good investment.
I have 4 thermometers and two hygrometers in my tent. I have found that making small adjustments (fan speed, fan location, amount of passive intake open) can make a big difference in temp. One of them is wireless so I can monitor temps without opening tent. This has been priceless for getting it dialed in.
I bet you'll be fine.
 
macsnax

macsnax

Well-Known Member
You can flip your fan so it's pulling instead of pushing air. If you supplement co2 this will help make it last longer too.
 
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