Building a box, need a bit of help :/

Hi guys, basically im building a box and ive got a couple questions about lighting. First off, the box is about 60x40x80(cm), made out of timber, its 12mm think, and the whole interior is covered in mylar. Now my question is, whats the deal with putting an HPS in there? would i definately need a reflector? Would it just get too hot for the timber? I dont want to leave home and come back to a burnt down house I cant put any extraction fans in there ive only got a desktop fan blowing at the plants for a bit of circulation. Im sort of thinking of just going for 2x 250W CFL's which ive found here
Basement Lighting Hydroponics and Grow Lights UK
Also i should mention that im growing Lowryder 2's in an aerogarden so the lights will be on 24/7.
Any help will be much appreciated, cheers!

well i think that you will be fine with what you've got. lol i've got a cardboard box 12"x15"x3' with two 1700 lumen flueresent lights and one of those heater fans for exaughst cut in the side and the plants are doing great

well the thing is at the mo ive only got 52W of cfl lighting, which is pretty lame, im after a nice yield really.

why cant you put an exhaust fan in there? with out one pretty much any lite will get too hot

i duno really i guess i just dont want the smell from the box getting out from the exhaust fan, i know i could put a carbon filter in etc etc but its still pretty expensive n im at uni so my budgets pretty low.

but yeh what i wanted to know was what will happen if i put just the HPS in there with no reflector just an oscillating fan? would it kill my plants?

bump? sorry to pester, but do you guys really want to be responsible for 7 dead plants?!?!

You are going to need some sort of intake or exhaust mate. The plants are going to need fresh co2 coming into it somehow. If smell is a problem, you are either going to have to not grow, or find some sort of odor control.

just a computer fan inside, is not going to bring in fresh air, its just going to circulate the old air thats already in there.

Hope you figure something out <3

the area seems kind of small.
you should mention how many watts the hps has.

am i doing conversions wrong or is 60x40x80cm a really small box?

Yeah i was thinking of a computer fan, but i wouldnt know how to wire it to the mains, dont they have a unique power connection that plugs straight into the motherboard? if someone could explain how i could splice the cable that would be perfect! Yeah the box isnt huge but im only planning on having 2-3 plants in there, plus dont forgert theyre lowryders, so they wont grow more than 25-40cm. my plans for lighting now are to have 2x 250W CFL's running 24/7, and then ill turn the 400W hps on when im home so i can keep an eye out. So your saying if i put that exhaust fan in there then the box wont overheat and burn? sorry for the noob questions, as you may have guessed it based on me using an aerogarden and growing lowryders, i am the noobest of the noob cheers guys

OpenDNS

Stoner

Join Date: Mar 2007​

Posts: 1,033​

Gallery: 14

​

permalink
You are going to need some sort of intake or exhaust mate. The plants are going to need fresh co2 coming into it somehow. If smell is a problem, you are either going to have to not grow, or find some sort of odor control.

just a computer fan inside, is not going to bring in fresh air, its just going to circulate the old air thats already in there.

Hope you figure something out <3

Click to expand...

I think you misunderstood, i have a mini desk fan in there atm circulating stale air, but if i got a computer fan id build it into the side of the box to bring fresh air in, would that be kosher?

ok well i bought 2 computer fans and wired them up to an old cell phone charger. One i put as an exhaust at the top left corner of the box and the other as an air intake near the bottom right of the box. i also have a mini desk fan in there aimed at the plants for circulation. You reckon this would be enough so that i could have the 400W HPS on 12/12 and the 500W's of CFL on 24/7? cheers.

shemi said:

ok well i bought 2 computer fans and wired them up to an old cell phone charger. One i put as an exhaust at the top left corner of the box and the other as an air intake near the bottom right of the box. i also have a mini desk fan in there aimed at the plants for circulation. You reckon this would be enough so that i could have the 400W HPS on 12/12 and the 500W's of CFL on 24/7? cheers.

Click to expand...

no, but if u add co2 to the room U might be able to get away with it.

Ur grow space is similar to mine. I have a hard time keeping my temps below 90*F even tho my intake is hooked up to my window bringing fresh winter air in. My humidity stays around 40% RH with the 400w HPS on.

And just so U kno, CFL's get hot too. so hot that they can crisp the leaves of the plants.

U may wanna invest in a cheap small air purifier from wal mart or sumthin, take it apart and mod it so that it fits ur box to extract heat.

set the oscillating fan to high and aim it at the HPS light, not on the plants. plants dont like direct winds bcuz it may cause wind burns.

as far as intake, check out ur local hardware store for duct booster fans. the work great for pulling air into the box. U can even hook it up to the window for better heat control and to pull in co2 from the outside air.

dude thats plenty of air. even one little fan will do as long as the air is moving a tiny bit and coming from outside the box. smell isn't a problem just fabreez it every couple days if it gets noticeable but with a little exaust fan and some holes on the top of the box it should be changing air quick enough that the smell won't add up and is not noticeable. like it would matter here anyways but if it does fabreez it

hemp4freedom said:

dude thats plenty of air. even one little fan will do as long as the air is moving a tiny bit and coming from outside the box. smell isn't a problem just fabreez it every couple days if it gets noticeable but with a little exaust fan and some holes on the top of the box it should be changing air quick enough that the smell won't add up and is not noticeable. like it would matter here anyways but if it does fabreez it

Click to expand...

I dont agree.

with 500W's of CFL's AND a 400W HPS its gonna get pretty hot.

so "air moving a tiny bit" wont do here. U need something to suck the hot air out, and u will have plenty of hot air. and U definitely need something in the 250CFM range to pull cool air in from outside so U can have plenty of co2.

I honestly think that 900W's is waaaay overkill for a few lowryders but thats my opinion.

febreeze wont work here either. unless Ur spraying it on ur plants (NOT RECOMMENDED). leave the household deodorizer for the couch.

some ways of odor control are to invest in an air ionizer, air purifier, carbon scrubber, or simply exhaust to the outside. hell Id even recommend one of those lysol "puff" deodorizers that spray every 15mins over febreeze.

a real old ghetto technique is to pour a few bottles of lemon lysol into a bucket of water and just leave it out side the grow room with a fan to circulate the smell. thatll pretty much over power anything else.

In that space, you would need more than a computer fan, but I would not overdo it with an HPS.
One word, overkill.
In this small space I would worry about heat and burn. Since it's only four feet tall, the 400w would take up roughly a foot, then your banking on small plants. Unless you want to butcher them if they grow too big, stay with CFL's and get a height extension if you could.
I try to answer everything but I miss out on lots usually, if you have more questions, I'd be happy to answer them privately.
Just make sure they get fresh air somehow

good luck man!!