will this work

If the timming is precise for every cycle it might i kinda got a feeling that your gonna have alot of males though I would suggest getting yourself some fans and moving out all of the hot air and bring in fresh air.

 

Do you have an air cooled hood? if you do just get a blower and suck all the hot air out or you area. If you dont then you can get a blower and just suck air out of your area (it wont cool the light as much as if you had an air cooled hood but it will help alot) or think about getting a small ac.

 

You'd have less females becuase your plants will most likley hermie from the stress of that light cycle. Your only option here is to improve ventalation enough to operate the lamp at the normal 12/12 rate.


edit: I can't tell you weather an open window would be enough, if you live someplace cold it might. Open it up and get in there with your thermometer.

 

500w? what kind of light is it???

 

Please describe how you envision this light cycle over a 24-hour period. All I know is it's on for 30 minutes, then what?

Basically, though, you need to give the plant the right kind and amount of light and figure out how to deal with the heat via ventilation, grow space design, etc. You can't deal with the heat by altering the light cycle.

 

get a timer and set it on 12/12 thats the only way

 

I think you have a security flood light..(halogen) .. Is that what it is? If so then dont use it. They get VERY hot and theres a high risk of starting a fire with them. Get a 400watt hps from a hydro shop or buy one online. If you have a budget get some cfls. That way you dont have to worry about putting it on for 30min then off for 30min. It wont grow right.
Even a 400w hps with a small fan wont get hot enough in an hour to the point you have to shut it off to cool. Dont touch it but if your area stays lower then 80degrees F. Then your fine.

 

All plants smell. Some not as much as others but if you know what a mj plant smells like youll notice it unless you cover the smell up with something like a carbon filter.

 

4M is 12ft right?

 

Hey man.
Take that halogen light you got there and throw it in the trash can. With a 3 foot fluorescent you probably have enough light to do 2 nice plants. Keep those two plants alive to the best of your abilities and 1, 2 or 3 years down the road, when your budget allows, you have 2 monster mothers (hopefully one will be female) to clone off of. Otherwise take the other 7 plants (because you are not ready for them yet) and either put them outside or throw them into the trash with the halogen light. Take it easy…

 

If you are concerned with yield then get some decent lights. With that 3 foot fluoro expect 1/2 ounce tops with 2 good plants or 9 crap plants either way, best case scenario. If you keep the halogen floodlight in there expect you won't have a yield because your plants have been cooked to death. If you can get some more 3 foot fluoros that would be great.