Hey guys just after a little bit of advise just built my grow room it measures 1.2M x 1M x 2.4M i have got a 400W hps light and a 4" extractor with passive intake. thought i would dry run my room to test the environment lights off it reads 17C bit cold i know and going to have to heat it somehow but the main problem is sat my thermometer 60cm ish away from light to act as the canopy and i am getting temps above 33C. don't really want to start adding more fans as i need 2 keep it quiet but will do if needed. at the mo i have a cheapo shade and thinking may be of going cooltube route. this is my first grow and a lil bit unsure but just want to get it right. any advise would be great.

thanks.

Hi m8
I would go for a bigger fan and a controler if funds alow i run a 600w hps in 1.2x1.2x2 and i got a highpower ruck 150l with a rinho filter and a primair works a treat apart for a bit sucking noise at the filter maybe try the low powered ruck with the 400w but i was advised to get a bigger fan incase of up grades and my 150mm fan turned down keeping my tent at 25c ir alot quieter than my 100mm vents tt running full blast

OK, first off, are you extracting the air to outside? This is very important.

Secondly, you are going to need at least one oscillating fan in there. The plants need more air movement than is provided by passive intake and active extraction. If you don't do this their stems will be weak and you may have fungus problems if any spores get into your tent.

Thirdly, 100mm extraction is totally inadequate for that space. Especially if you're using a carbon filter. If you're not using a carbon filter, you should be!

I have a 1x1x2 tent and recently upgraded to 150mm extraction because 125 wasn't quite cutting it. If you have an air cooled light, you might get away with 125, but depending on where the grow is set up, you're probably going to need 150.

Good luck!

hey guys thanks for replies.

wez - bit short on cash atm so cant upgrade and also i heard them primairs make a buzzing sound are u using just passive with ur 150 fan?

eri - the room is upstairs in a spare bedroom, im extracting into loft space atm. i do have an oscillating fan in there but doesn't seem to be doing much. when i went to get equipment the shop owner ensured me that 4" high powered would be fine even tho i intended to get 5" im not using a CF atm but intend to in flowering weeks.

thinking of taking a trip back to shop and exchanging filter for a 5" and swapping the 4" for intake and getting a 5" for extract do u think this is fine i don't intend of going bigger than a 400W? only prob is i need the fans to run quiet i have allready done the diy acoustic box with acoustic ducting and is still loud fan is running on full tho..

Investigate led technology for use in enclosed spaces. I am doing some trials. freinds of mine use it and it works, I have not done comparrisons with hps, the electric bills are cheaper info at

Wow, spam more?

LEDs seem to suck for growing.

Sounds like a plan to me

Have the intake blow on the light and you should be able to get the temp down to a reasonable level with that setup.

Eri - just had a quick flick through ur diary like what u did with the intake pointing at the light + floor think im going to do something similar

Had a big think and going to change the 4" to intake and then invest into a 5/6" fan depending on cash (just thinking ahead as its November and im struggling to keep temps down summer going to be mission impossible!)

Yeah man, I very nearly just added a 4" intake and left the 5", but my humidity level was also way too low so I knew I needed to up the extraction too.

A 5" intake is possibly an overkill, but the diamond reflector creates a hell of a lot of heat! I really needed to get more cooler air in there.

If you can spare the cash, I would definitely go for the 6", but if your humidity level is reasonable already and you're not using a diamond, I reckon you'll be ok with a 5".

Bear in mind, that a 6" will give you roughly double the extraction rate of a 5" too... they seem pricey, but when you look at it that way it's definitely worth the extra.

where is your thermometer positioned m8? if its directly in the light it will give an artificially high reading it needs to be shaded.

dakter

I'd second that before you go changing kit.

Hey dakter and OG my thermo was sat right under direct light about 60cm ish away...

Going to re test the room with the thermo under a little box and test the top of the room as in therory this should be the hotest point???

hi m8 im using a cheap ventts inline 150mm fan 305m3ph i do get alittle buzzing with the primair but it cant be heard out side the room ive seen diy fan controlers on here if your any good with diy i dont think there that dear to make the go for 150mm fan it will save you cash in the long run m8