I was wondering if anyone is using a cool tube? I was planning on making a small closet maybe large enough to fit a small ebb and flow system, i'd have to figure out the exact dementions later, but would only be about 3-4 ft tall, I was thinking of getting a cooltube.

Now I have a 400 watt ballast, my question is, should I put in a 150,250,or 400 watt bulb in there for the cooltube? I don't know exactlly how cool the bulb will be within the tube with the different wattages,

Does anyone have any info on this?