# 2x600w cool tubes - what´s the perfect circle?



## MikeGanja (Nov 29, 2013)

Hi,
When growing vertical in a 360 degrees circle, with cool tube (2x600W), what do you consider being the most efficient diameter of the circle? If you have done experiments on distance to the bulb and total yield please let me know. Those of you that have tried cooltubes but prefer bare bulb, do you get a significant better yield with bare bulb in your vertical grow? 

Regards


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## Prawn Connery (Nov 29, 2013)

This will answer a lot of your questions: https://www.rollitup.org/vertical-growing/741494-cool-tube-vs-bare-bulb.html


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## MikeGanja (Nov 30, 2013)

It certainly did, thanks!


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## sidhu35 (Dec 2, 2013)

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## SmokinErb22 (Dec 15, 2013)

Unless you have heat issues I'd probably toss the cool tubes aside. Or unless you have plants growing into the light and you're using it as fire prevention.....but since you're asking about the ideal size cab for your lights I assume you're in the planning stages. 

I'd suggest a 5x5 for stacked 600s. A 4x4 would work but you would yield less. A bigger circle means more sqft of canopy.


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## OGEvilgenius (Dec 16, 2013)

Cooltubes rob significant amounts of light. With proper extraction they are unnecessary completely. Just make sure you're extracting your room 2x a minute and have a small fan blowing up from below your bulbs. Use trellising (homemade or whatever) to control where the plant grows. Probably the most difficult part is finding a good strain that you like that grows appropriately.


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## SmokinErb22 (Dec 16, 2013)

^ Agreed.

Strain selection is important. You need something that stretches, stout indicas just don't fare as well. 

Another thing to keep in mind is that it's EASIER to cool a vert set-up because you don't have a massive radiator above your light trapping and holding heat (even air cooled hoods hold heat - put your hand on the hood). 

2x a minute exhaust as stated above and a small fan below SET ON LOW (that's important!) blowing straight up. Many tests out there that show a slow gentle column of air helps cool better than setting the fan on high, blowing the hot air every which way in the cab. Fans on low result in lower temps than fans on high.


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