do i need a cooltube for a 400 HPS

does 1 single 400 watt HPS need a cooltube
and also
will just one HPS be sufficient for a medium size closet?

4 plants ideally...

and are there any other fire dangers associated with highpower lighting in a closet?

thanks everyone

You will likely end up needing a cool tube...

In terms of safety, dont keep the light near close, make sure it is hung securely, make sure the ballast will not catch anything on fire if anything ever SHOULD go wrong. make sure if you wired your own ballast, it is correct.

keep everything cool, and make sure your circuit panel is comfy as well

You prolly wont need the cool tube during the winter, but summer is a def. I had to run my ac 24/7 this summer. Then when I went 12/12 I still had it on for 12 hours to keep my baby cool... I myself was looking into a vented hood which is better a cool tube or a square hood with the sealed glass? I already bought two 6" inline exhaust fans just wondering what hood I should get.

Check out my new grow space
https://www.rollitup.org/general-marijuana-growing/119033-2nd-week-flowering-white-widow.html