250 or 400 watt? Will it work? Advice welcomed

Whats up fellow tokers.

Currently I am not able to set up my DR80 tent so I am trying to grow in a small wooden cab. The dimensions are 30" high x 36" wide x 19" long.I am growing norther lights autoflowers which I have lst to keep from getting too tall. They are 4 weeks and two days old so there is about probably around a month left in their life.

I have a 6 inch cooltube with a switchable 250/400 watt ballast. The cooltube fell off by bed when I was working about a year ago and is missing a chunk out of the under side of it, the rest remains intact. I have this cooltube hooked up to my 6" 400+ cfm fan which is connected to my carbon scrubber where the air is pushed out.

I have exactly 22" from the bulb to the ground. My plants are 15" tall at the moment which gives me barely 7" of grow room.

My question being. Is this possible to finish the two plants I have now with the limited vertical height. With the broken cooltube the air comes directly in from the middle of the tube instead of the side.

Is a 400 watt overkill for this area, would it be a better idea to run a 250 watt bulb instead. I am just trying to figure out if this is possible at all or should I start redesigning my light and ventilation system. I wouldn't want to have to change the set up once they are already in there and problems arise.

Thanks for any advice!!!
Indi

 

Electricity is not an issue for me. Although I am trying to stay under the radar. I wasn't sure if the amount of room would be enough without burning the plants. I had been vegging with cfl's and my 400 watt was sitting in the basement getting dusty. I feel the need to utilize the 400watt for the remaining days of flower. what would you say a 400 watt lumatek digital ballast plugged in does to the electricity. Is it like adding a new tv or a heater for the winter? I never had problems using it before I just get paranoid sometimes using the big lights.

I figured they only have 3-4 weeks left to flower which wouldn't give them enough time to reach the light. Hopefully lst them down does the trick.

Now to put a door on this cab and insulate everything to kill the noise from the fan. This blower makes a lot of noise sucking the air through the ducting.