Hello all got some thai seeds out of a bag ! dont think there pure sativa, but anyway grown them up to 10 inches using 125w ecolight blue and have now just purchased a 600w hps lamp my grow area is 3ftx3ftx8ft ! i was thinking of going without a cool tube because my grow is in a closet drobe with an attic hatch at the top! If i opened that hatch would dust become a problem or could i somehow use material to stop dust coming in? or would i have to go for the cool tube?

or would a couple of pc fans in that hatch be usefull for extraction? the attic isnt well insulated would this be ideal ! you know what ill take a photo! ill be back!!

i know pc fans dont have the pull but surely they will help?

pc fans wont cut it with a 600 youll need proper extraction , i was gonna say you might struggle with proper extraction

defo not with pc fans

Cheers! struggle with extraction ? because of area?

when you fire that 600 up its gonna get hot , what are your temps with the ecolite ?

400w gives you 49watts per square foot thats perfect and not as hot

i got my ecolight down to 25c but that was in a 3ftx3ftx2half ft high using pc fans and tumble dryer ducting and 6 inch fan inside grow room

a 600 is to much and you will need good air exchange even for a 400 these hid lamps get hot

not like enviros no touching these bad boys

even with a 2ft x2ft open hatch into my chilly attic?

and fresh air coming from where the open hatch isnt actively removeing anything, of course it will head that way but that aint enough imo

fire it up and see what your temps do

ok firing it up now!

I used to grow in that cupboard in my old house a few years ago....

Managed okay with a 400w lamp and the hatch just open, but when I upgraded to a 600w I needed to use extraction....I think I only used a 4inch fan at the time and it was fine, except in the heat of the summer....

A 5inch fan will do the job for you, drill out some passive vents near the bottom of the door and fit with baffles to prevent light leaks.....

They can be very productive spaces given the right conditions..

Monk...x

i used to grow in a cupboard at the top of our stairs which sounds the same size as yours with a loft hatch,with my experience,i would just do it right from the start,i tried and failed to passively cool a 600 watt light,ended up with 4 grill vents in the door,with carbon filter behind to stop light leaks,and a 150mm ruck L1 fan for extraction,still couldn't grow all year around.so bought another 150 ml fan for active inlet and 600 watt air cooled reflector.
Don't forget you are going to need some sort of extraction with a carbon filter,to acheive negative pressure ready for when they start stinking,so your whole house don't smell .

thats what i was gonna suggest, 125 for extraction and a few passive intakes, then see what your temps look like,
you are gonna need to get fresh air in there.

fired it up gonna giv it a while 2 build up heat ! for the 1rst few mins its staying at 25 but guessing it will build up

can the smell go through to the neighbours?

31 degrees c at the mo but aint hanged the light or done anything just put it up the corner the thermometer is 1 ft away from the light! no fans just the vent! ill check it out again in 20mins!

I appreciate everybodys contributions !

you need fresh air and old air gone extraction is the answer and a filter to remove the smell , give them a good home and they will repay you

if you dont you are asking for problem , eviroment is number 1

still at 31 surely if it stays like that pc fans and ducting to the window should get me a few less degrees! but ill have to see once the attic fills with warm air! then again i am a builder so putting a slight whole in the roof shoudnt be a prob! i might cut a brick or two out and get the fresh air from there!

I did an 'open top' grow in a 30" x 30" cupboard and a 400w, passive vents at the bottom. tbh I've never had colas since like those NL gave me, even the same strain done in an XXL tent under bigger lights didn't match them, maybe it was the proximity of the walls.

Extractor fan or not you'll either be needing vents at the bottom for passive intake or a fan for active intake. Ebay do some good fans, I got a 6" 290m3h for less than 20 quid delivered. It's currently taped to a 6" carbon filter in my bedroom while my newly harvested crop dries.

gone to 36c

During Flowering without extraction under a 600 or 400 they are gonna Stink. My first grow under a 250 a few years back you could smell it at the end of the street at certain points in the grow. Also I beleive thai's can grow fairly tall and when you got a light and reflector hanging in your drobe you are gonna lose some height and you need space 6-18 inches from the lamp.

I grew for about 7 years off and on like that - mostly with a single 250, but did two grows with two. In fact my earlier 250 watt grows were even more poorly ventilated ...

I probably got away with it because next door was empty for years, and latterly occupied by people who chain-smoked and had a smelly dog and a liking for shake and vac. The roof was poorly felted too.

But you shouldn't even consider it if you have any kind of a life ...

Try hanging the light high and holding your hand under it, about 2 foot from the bulb for a full minute. If your hand doesn't get too warm, neither will your plants. If the reflector needs to be a bit higher than most growers, so be it.

So is there an easy possibility of fire with a 600watt? if not ventilated well? temps were still 36 this mo, contemplating getting a cool tube for safety!

Ive been training them so far just in case they grow tall!

Ive been training them so far just in case they grow tall!

You're pissin in the wind without proper extraction mate, never mind the fact that you will definitely need a carbon filter, even in veg they can stink. Is it worth getting busted for?

The extraction fan isn't there for cooling, it just so happens it takes care of that too. Plants are made from carbon, there isn't that much in the air so a fast exchange is needed to refresh depleated co2. The only way of not using extraction fans is to seal the room but then you need co2 injection and air conditioning. Trust me that will cost a fortune, never mind getting co2 tanks into the house without arousing suspicion

Cheers a proper extraction it is then! Thanks for the advise much appreciated!