For a first timer you're doing great IMO, especially with what you have :thumbsup:

Yield is a tough one... 40g per plant with a 150w is possible, if you veg long enough (maybe 6-8 weeks I'm guessing??), but whether that light will cover all 4 and still give you 160g... it's possible... but maybe a QP would be more realistic IMO (note: never used a 150w before).

I'd recommend looking at this thread: http://boards.cannabis.com/indoor-li...-lighting.html Check out post #7... and look for those things at Wal-Mart. It's a cheap and easy way to get more light, and might get you to your goal of 6 oz.

Happy growing:jointsmile: