Yes, Right now I only have one 400 HPS (PL Light system). Pricey. I hate to have bought it for nothing only to buy another cheapo 1000w or 600w. And the 600's seem expensive and almost the same price as a 1000w.

So I thought if I got another 400w light, I could run them together during bloom times to get 800w. Then, having 2 separate lights, I can still have the option to use one for veg & one for bloom at the same time. Currently, I have one of those flouro shop lights and a few CFLs if the 'real' light is in use.

Would (2)-400 HPS's give off MORE heat than (1)-800? (hypothetical).

I guess the 2 lights makes sense for me. The only question do I get another 400 or another 600? If I go 400/600 - then I have 1,000. Just not sure if 2 lights of the same wattage are better than one?
LOL - I'm befuddled about this. I would just like to have fat buds like I see in pictures vs. my thinner little guys. Since I'm doing all this work. You know?

EDIT: Yes, everything is mylar'd. Except ceiling.