400w HPS too much for 2 plants?

Hey RIU!

Here is my dilemma. I am growing 2 plants in a 28" x 20" x 60" cabinet. (The cabinet is actually 6' tall, but my top foot is where my electrical and exhaust fan is.) I wanted to buy a 250W HPS for when the girls are in flower. I am having a hard time finding one on ebay or amazon that is in my price range. Believe it or not, the 400w MH/HPS is much cheaper than the 250W. Heat wont be an issue, so would 400W be too much for 2 plants?

That is a lot of lumens for a small space. That's 13,000 lumens per foot. I can't answer if that will be ok or not. I just don't know enough about it.

How are you controlling heat?

I just looked up the 240 w lights. Yea, crazy expensive. I picked up a high end 400w adjustable hps ballast, good hood and new bulb for $100 bucks on CL. Hard to beat that price. I paid $80 for my tiny 150 w Sunsystems new.

I got a 400w revolt? From gotham hydroponics ebay shop (free shipping on eBay but not their website) it can be turned down to 75% and 50% power and ruin hps or mh

If heat is not an issue it should be fine.

Its not that there is too much light, its more of the area you are useing a high heat light in the space.

If you have a decent set of fans then you will pull a decent yeild from the space with the amount of light your useing,i would cut the plants down to one though.

Get your hands on a 12" out let and 8" inlet an you should be fine,i would also try my hardest to get the money for a cool hood of some sort even a cool tube,

And the best way of getting a good yeild from a space of that size is to scrog,that way you can flower at a decent size say 2 ft and control them so they end up around 5 ft,that would be 1 ft under the height you have.

I'm not sure if a shop called the kitbagshop deliver world wide but well worth a look they do some nice products a very good price range

This light is pretty versatile for the space you are dealing with: http://www.growwurks.com/sun-system-digital-250-400-watt-120-240-volt-mh-hps.aspx You can use either MH or HPS and select either 250w or 400w....and you can hook it up with 120v or 240v. But it isn't vented. Personally, I don't think 400w is too much.

you'll be fine bro just keep the heat out the area and like you said you already have a fan at the top of your cabinet so you should be fine also keep a fan blowing around your girls so the warm air doesn't make them too hot

Don't panic if the temp are high go on the plants if they look ok then they are ok,i no longer use a temp gage.they will tell you if something is wrong but i do use a humidity gage this is important during flowering

I'm growing in my garage. I live in a very cold climate. It's been about 5 F outside for the last couple weeks. My garage is heated to 40 degrees, so that's the temp my intake air is. I know it's not the best and I should have waited till spring to grow, but it is what it is.

Right now I have a thermostat installed in my cabinet attached to a space heater. It has been keeping my temp between 68-77 degrees.


I figured with the 400w HPS I wouldn't have to run my heater as much. I'll just keep my exhaust fan on 24/7 and always be pulling in cool air.

How hot would a 400W MH or HPS make the cabinet if the intake air is 40 degrees?

I used to grow a single plant in a 22.5" x22.5" with a 400, pulled 121 grams the first run

https://www.rollitup.org/t/new-growbox-w-jedi-og-kush.645733/

and about 140 on my second go around with one plant also Also crammed 2 in there a couple times, but was too much work.

https://www.rollitup.org/t/strawberry-dream-grow.674018/

It is a challenge with heat and trying to get any kind of airflow, but you are more likely to have issues trying to keep it warm enough if your external temps are only 40F