I read the instructions on the cool tube..genious i must say GT solved alot of my thought to be problems off top.Got a couple questions.I plan on growing in 2 (i was going to grow in 3 but 2 will do), 4-6" pvc pipes cut with 4 grow holes a piece.With the 2 pipes runnin parrelel(NFT).Would this cool tube keep the light cool enuff to put a 600watter directly in between the plants to limit the shading from the leaves.I know it would probably create shade for the sides but how bad and would it be a good idea.i also plan on putting 3-4 24" flouros on each side of the plants
keep the cool tube above the canopy. gt420 says his 400W is cool to the touch (he can grab the tube while the light is on with no discomfort) so the buds could grow right up to the tube with no problem. i don't think shading is as much of a problem as you might assume. if you're that concerned about it then maybe you could have 2 cool tubes. a 400W above the canopy and a 250W down in the middle of the plants.
Mellow is correct however there is limitations. my plants will grow right to the bulb however if i keep it too close at 100 watts per sq foot it can and will cause mutation plants can only effectivily process a certain amount of light..Plus it can cause light stress which will appear as a bleached out leaf. I keep mine about a foot away but for a couple days right next to the tube they are fine. Really the main purpose of a cool tube for bigger lights such as 400 and above is overall ventilation and heat. Now as far as smaller lights 250 and under you can grow plants right next if not touching the tube. hope that explains a little confusion and i should have mentioned this earlier but i'm learning this setup as i go.
