HELP. First grow and having temp issues. Couple of questions

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Freddy7815

Member
Firstly, thanks for lookin at the thread


Did a lot of research and got the following set up but having real temperature issues.

Set up is in a tent with dimensions 2ft x 2ft x 5ft height

so ive got:
400w hps which is dual spec.
5 inch cool tube.
5 inch RUCK extraction fan.
5 inch carbon filter
5 inch ducting

goes: filter > fan > ducting > cooltube > ducting out of tent

also have:
passive intake.
and in tent 12 inch fan for air circulation
and in tent 6 inch fan also.

however my thermometer (which is stuck onto the side of the tent) is reading temperatures in the high 90's farenheit??


obviously the space directly in front of the fan where the plants will be is cooler but with the overall heat of the tent being so high will i kill my plants? :-(

any advice? do i need active intake of air?

ive got 5 seedlings which i germinated in paper towls, now in coco and on my windowsill and are just about breaking the surface.
really want to fix the temperature issues before placing them in the tent, glad i tested everything for 12 hours first.

thanks for reading!

also when would be the best time for them to go under the 400w hps?
 
Illegal Smile

Illegal Smile

Well-Known Member
That's too hot. You have more heat being generated in that small space and not enough being extracted. Plus the air outside the tent must not be cool enough so that what is drawn in (not enough) balances the heat. My first impression is - do you really need the tent? It's like putting a blanket around the grow the way it keeps heat in. The other solution is get more and colder air in.

ps - can you put a 250w MH in that setup? You don't really need light until you start seeing green.
 
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Freddy7815

Member
Thanks for the reply.

the tent is inside a cupboard built into the wall with pretty much the same dimesions.
the reason for the tent was it has a metal frame to hang the fan, filter and lights from so there wouldnt be a need to start drilling screws into the wall and such, and also has a reflective material.
also wanted a sealed enviroment to control smell if the plants reach flowering.

and the reason for the whole lot being in the cupboard is it needs to be a stealth grow.
door of cupboard is left slightly open with the extraction duct blowing air out of the cupboard.

i had read the 400w in a small tent could be done with a good fan and cooltube (not so in my case...) and that to get decent buds you need at least 400w... which was why i got it.

ive already spent a lot of money on getting all the equipment and nutrients etc, i take it i would need to get a 250w ballast as well for one of those?
and would that be for just vegging or for the whole way through. i was going to go 12/12 from seed.

i dont know if to spend more money down grading my light or spend money on getting cold air into the tent..
 
UKHG

UKHG

Well-Known Member
you dont need a tent for a 400 watt light no way they will see it id take the tent down and just paint the walls white and hang light from celing u can always fill it and thers no crilling u can get screw inplaster raw plugs
 
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Freddy7815

Member
thanks for the replys.

i'll get rid of the tent and set things up differently.
going to get a fan to suck cold air into the cupboard as the extraction fan isnt doing enough.

hope this works and i'll post any success.

any more advice please let me know.
 
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gotigers0420

Active Member
how many cfms is your fan? is the hood sealed? right now your trying to cool the light with already warm air. if the hood sealed, just pull in cool air from outside the tent, over the bulb with it and out the other side of the tent. skip the filter and the hot air youre trying to cool with.
 
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Freddy7815

Member
gotigers0420 said:
how many cfms is your fan? is the hood sealed? right now your trying to cool the light with already warm air. if the hood sealed, just pull in cool air from outside the tent, over the bulb with it and out the other side of the tent. skip the filter and the hot air youre trying to cool with.
Click to expand...
dont know about cfm but its a RUCK 5 inch and says its 295m3/hour, yeah the hood is sealed ive checked for leaks.

if i cool the light with the new fan ive ordered and have the current fan just extracting the hot air, ive still not got cold air coming into the tent. and i need to drop temps by about 15f

do you think it would be best to have A or B

A:
one fan filtering the air and blowing that air over the light and out the tent
then another fan sucking cold air into the tent

B:
one fan filtering the air and blowing that out the tent.
another fan sucking air in and blowing that air over the light and out the tent.

option B has more efficient filtering/extraction and cooling of the light.. but there isnt fresh cool air coming into the cupboard other than passive intake and i think thats why the temperature gradually builds to be so high.
or would B being more efficient mean the heat wouldnt build up?
 
F

Freddy7815

Member
Enzogrowspot said:
Hey bro, ya I would have tried to run it without the filter just to see if the temp came down.
Click to expand...
i wanted to try it with the filter incase when i put the filter on later it became to warm.
but the temps are over by 15-20f.
could the filter make that much of a difference?
 
F

Freddy7815

Member
my air is pulled through the filter.

this is the set up


set up.jpg

should i change it to:

set up2.png

or

set up3.png

what do you think? really need these temps down. :?
 
scroglodyte

scroglodyte

Well-Known Member
too many bends.......can ya straighten out the circuit? and i don't understand the difference of the two schematics. the third looks the best
 
F

Freddy7815

Member
well my temps are too hot so i think adding a second fan is whats needed.

either increase intake into the cupboard as the passive intake into the cupboard is next to nothing (which was the first alternative picture)

or use a second fan to cool the light, and letting the current fan just extract (second alternative picture), as my current set up uses the filtered and probably already warm air to cool the light.

so you reckon go with the second option then.

with regards to the bends, with the way the cupboard is built into the wall my entry and exit points are very limited so i need to bend the ducting. :/
 
smokey de bear

smokey de bear

Active Member
Hey Feddy I'm going threw the same trials and tribulations as you are at the moment, trying to fine tune the vent system. And I to was debating between the same 3 options as you are, what Ive been doing is the ol' trial and error way. Tonight I tried just putting the exhaust duct near the 400w hps and near the top of the room with a fan pulling air out, with passive intake I ended up with high temps. I like to keep things simple so tomorrow imma go make me a cool tube out of an oil lamp glass tube, duct tape and put it over the bulb and let the air suck threw the tube like how you first had it setup, if that dont work then im going to move onto isolating the two systems one bonus will be no need for a carbon filter for both systems. Let me know how your experimentation goes, ill keep ya posted on my progress my setup is all pretty ghetto but works I'm a big DIY'er.

Good Luck,
Smokey
 
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gotigers0420

Active Member
option 3 for sure. You have to cool that light with some colder air, then deal with temps. You maybe suprised that once you get light cool, the rest will takw care of themselves. good luck
 
smokey de bear

smokey de bear

Active Member
gotigers0420 said:
option 3 for sure. You have to cool that light with some colder air, then deal with temps. You maybe suprised that once you get light cool, the rest will takw care of themselves. good luck
Click to expand...
I read on a post somewhere that he had setup his cooltube as an isolated vent like option 3 and his temps were still high so for fun he disconected the intake side of the tube and was basicly using the cool tube like the first picture without the filter and got 8-10 degres cooler theory was it was sucking the warm radiant yucky air in there as well as isolating and extracting the light heat.
 
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