vertical grow light question

Im planning a future grow very similarly to heaths flooded tube system but i plan on utilizing floor space as well. I want a similar sized room to Heaths but maybe a foot or two taller to incorporate an additional light.

So the question is would an additional 600 watt light be worth adding to heaths setup? And can i expect twice the yield because the additional bulb?

Just wanna see what i can tweak as far as size of room and such so any help is appreciated

You'd have to add some levels to his design, but yes, you can expect to increase your yields dramatically. If you up the plant site count you can further increase your yields and if you are skilled enough to build something circular (and have the tools and materials) you will even further increase yields.

Boy, Advanced really knows how to market...