help with a cool tube

I have a question for you guys. What do you think would be better, a cool tube with an internal reflector lining the inside of the tube or an external reflector over the cool tube?

With the internal reflector the light will not have to pass through the glass as many times, increasing light transition however it might not focus the light as well as an external reflector.

external reflector. The metal will not get as hot and you can make a bigger/wider reflector to give the plants a more even distribution of light. Whereas a tiny reflector inside the tube would point the light in a more direct area.

ok sounds reasonable. Any ideas on what the best kind of reflector is for keeping temps down? A batwing maybe?

have you considered a bulb with a built in reflector? ive heard those work pretty good

i already have a hps bulb. I would like to avoid ordering online. thats why i like the diy stuff.

You can create your own reflector by getting a sheet of aluminum at Home Depot, bending it to form a hood of your choice/size, and use some hose clamps or something to hold it to the cooltube. Voila.

make sure its like a hammered texture to avoid hot spots

yah i plan on using the aluminum and painting it white but i am unsure of what shape of reflector to use to keep temps the lowest.

With my 400htg cool tube. I used the a batwing style reflector it works great. I get good coverage and my 400 is always cool

yah the batwing sounds good. Is it good for creating a rectangular radiation pattern?

I had good results with a 250W HPS in a homemade cool tube (it was some kind of pyrex baking tube) under a batwing reflector.

thanks joe that is exactly what i plan on doing. how big did you make the reflector?

Not to intrude but how to cool hps if can get a vent tube to fresh outside air?

you want to pull air across the bulb and out the exhaust.

Would the only way be a portable air conditioner?

Idealy you want cool air from outside the tent, cabinet etc, to be pulled across the bulb and then exhausted outside of the same grow area.