Anbesol ~ I did a search on that title and found quite a few sections of the book and related material on-line. Made for some interesting reading. My wife is convinced that the more I learn about this the more new toys I need to buy.

That brings me to the reason for this post. The little woman gave the go-ahead to get an HPS light. I know, this was supposed to be a CFL grow. Well, it was a CFL veg......

We'll keep the CFL set-up for vegging but we are looking forward to more production from flowering with an HPS.

I'm looking at a 400 watt HPS/Cooltube Combo at HTG Supply. One question is: Is it worth the extra $40 for a digital ballast?

I figure I may need another fan to cool this light considering the problems I had with bends in the duct tubing.

http://boards.cannabis.com/indoor-gr...-up-night.html

As you can see, getting rid of the duct tubing with it's bends took care of my cooling issues. Right now I'm running a 500 CFM 8 inch in-line "booster" fan. I have another 4 inch booster fan out in the shop. I'm wondering if I were to set it up like this if I could spare myself the expense of another fan.

Carbon filter - 4 inch fan - flex duct - cooltube - flex duct - 8 inch fan

On another note; I crunched the numbers using Miss Stinkyattic's formula from one of her stickies and found that running the HPS is actually about $5 a month cheaper on the electric bill than my current set-up.