You can use these for up to 1000W I believe, as long as you have a good inline fan (450+ CFM) should be good. For 400W-600W 200CFM should be alright, but I like more airflow to maximize the cooling effect. In the photo a 150W bulb was used yes, but up to 1000W should fit fine.

It is definitely a worthwhile project, you could save hundreds depending on how big you decide to make your grow room.

Lets just compare really quick:

250W ballast kit - $47.00
250W HPS bulb - $10.00
250W MH bulb - $20.00

$117.00 for full cooltubed setup (DIY style) includes bake a round, all parts, etc.
$189.00 - $304.98 on ebay


400W ballast kit - $65.00
400W HPS bulb - $18.75
400W MH bulb - $20.00

$133.75 for full cooltubed setup (DIY style) includes back a round, all parts, etc.
$189.98 - $339.95 on ebay

600W ballast kit - $82.00
600W HPS bulb - $25.00
600W MH bulb - $35.00

$172 for full cooltubed setup (DIY style) includes bake a round, all parts, etc.
$250.00 - $930.00 (48 inch setup)


1000W ballast kit - $120.00
1000W HPS bulb - $30.00
1000W MH bulb - $30.00

$210 for full cooltubed setup (DIY style) includes bake a round, all parts, etc.
$325.00 - $411.90 on ebay
Those prices vary, depending on seller, but the lower pricing depicts the level of quality they use as well. I would much rather build it myself and cost way less. Than buy it from someone and pay way more.
THContent Reviewed by THContent on . DIY: How-to Make your own Cooltube (inexpensive) Well, I looked on here for a "Do it Yourself" for making your own Cooltube on here, couldn't find anything, so here goes: How to Make your very own cooltube setup! The very best way to do it. This is of course, by no means a new idea. This is simply meant to be an informative tutorial based on my experience while searching for a cool tube solution. I was unable to find any detailed or clean instructions on how to make a cool tube using a Pyrex bake-a-round. They all leave out small Rating: 5