Two things:

1. If you dont get the cooltube you will wish you had in a month or so.
2. If you get the 400w you will wish you got the 600w in a month or so.

Personal XP.

__________________
!Warning! The above post is filled with sarcasm and bad humor.

I went with the 400 cause i have about 5 sq ft of tent to grow in. That is still over 80w per sq ft. As long as I keep the light close I should be able to get close to a gram per watt from my 18 plant sog.

600 is my next step though. Will have to move first.

__________________

AMMENDMENT 20 COMPLIANT - Rocky Mountain High

yea its all on the size and number of plants u want to grow... ofcourse the higher wattage ones are better.. but really not needed if , well , u dnt need it.

__________________
Everything I say is based on fiction, and all pictures were taken from the internet.

it will lower your lumens so will not neccesarily increase yield depending on the conditions you normaly grow in it might actually decrease yield. the reflector on cooltubes is a complete waste of time they dont give a nice light spread at all and you waste a lot of light as its not concentrated in the right way, sputnik air cooled reflectors are much better and only slightly more expensive, only drawback is you need to silicon seal it if smell is an issue as its not a sealed unit like the cooltube.

The internal reflector on the cooltube is a concern but it can be removed. I am thinking I will remove it and attach the tube to a DIT batwing reflector.

I thought about just DIY cooltube but I had a hard time finding one of those bake-a-around tubes for less that about $20. That would put the DIY cost at about 40-45 with everything else. The one I bought was only an extra 65 so only $20 savings. . My time is more and more valuable as i grow older so it wasn't worth it to me.

__________________

AMMENDMENT 20 COMPLIANT - Rocky Mountain High

Cooltubes and their ilk suck. It's on of the worst designs ever. As stated, re internal reflector is a joke, but putting on an external reflector is only marginally better. In order for much of the light to reach your garden, it must pass through the bulbs glass, the cool tubes glass , off the reflector, back down through cooltube glass, and past the bulb through the cooltube again. Pretty cappy since that glass takes 10-20% each time, as well as slightly altering spectrum unless your cooltube happens to be made of tempered low lead glass, which it isn't. Cooltubes do one thing good, cool, everything else about them is subpar. There are much better ducted reflectors on the market. I know it's too late for this grow, by next time factor in geometry and physics into your purchase. Lots of people will tout how awesome cooltubes are, but science trumps anecdote anyday.

__________________
Don't incarcerate self sufficient sick people. I grow cannabis for ulcerative colitis and to relax. http://www.rollitup.org/grow-journal...ganic-s-c.html

what would you recommend for a hood then? im in the market, and i was thinkin a cool tube.

Your figure of 10-20% is overinflated. As long as the glass is clean it is not that high. I got the recommendation for a tube from the best grower I know so i went with it. For superior heat removal there is nothing better IMHO. The air cooled hoods do not have great flow and radiate heat that I didn't want. THanks for the reply anyway. Cheers

__________________

AMMENDMENT 20 COMPLIANT - Rocky Mountain High

my numbers are based on a test using sixteen points of measurement in a 3' grid. I used a digital lux meter. Tests were done at all sixteen points and at 1', 2', & 3' high. A Pyrex baketube, sunleaves maxtube, sun system lightpipe, and bare bulb were tested, as well as several other reflectors (my grow shop loves me). Internal reflectors on the tubes, as well as external gullwing style on the tubes and bare bulb. I may not have clearly worded my statements earlier. Total loss when traveling through ALL glass fields resulted in minimum loss of 8.39% and maximum loss of 21.78% at single points within the grid. Averaged into all measurements, a loss of 3-5% was seen. When using the internal reflector on the tubes the problem was the worse. I used the bare bulb as a base measurement for calculating each setup's loss. There are times when the cooling benefit outweighs the lumen loss, but other reflectors on the market can fix this issue and still give even light spread. I tested with clean glass, and with finger smudges and dried spray also by the way. All I can say about that is keep them clean. Good luck with your grow. Yacky da!

__________________
Don't incarcerate self sufficient sick people. I grow cannabis for ulcerative colitis and to relax. http://www.rollitup.org/grow-journal...ganic-s-c.html

the best reflectors on the market for potent, even light spread over square or rectangular canopies are PL Lighting Systems. But they are pricey, and require slight modification to properly keep the glass cool. They are properly designed by Hortilux and have various models for different spreads or wattages. At 12" from the "deep" model, a 400w solarmax hps has 80% the output of a 600w solarmax in a sun system enclosed digital ballasted model, averaged from a 2' square. At 24" it had 20% more output, and at 36" it had 60% more. Both bulbs tested were new ones that had been left on for 150 hours prior to testing.

__________________
Don't incarcerate self sufficient sick people. I grow cannabis for ulcerative colitis and to relax. http://www.rollitup.org/grow-journal...ganic-s-c.html