Seriously, Do I have enough light?

Alright, since I'm not happy with my most recent harvest, I want some opinions.
I have a Sunblaze 48" Fixture. With 8, 4 foot T5 Flo Bulbs. High Output at 5000 Initials Lumens. That means 40,000 initial lumens for the fixture. This is in a standard closet. Is this enough light to grow anything substantial? Now, substantial to me means 5 plants. Do I need more light? Since everyone's gonna answer yes to that. What can I expect to get (harvest) with my current light, just a ballpark? I can't upgrade to an HPS or MH, because I don't really feel comfortable cutting in an exhaust into this room.

This was my second grow. WW for the second time in a row. I used LST method this time, normal grow last time, harvested quite a bit more last time. This time, the buds seem very leafy, any connection between obscenely leafy buds and lack of light?

I'm just looking for some input guys. Any help is greatly appreciated.

Hey Raven,

You should have plenty of light if the figures you gave for them lights are right, 40,000 lumens, a 400 hps don't put out much more than that, so plenty for 5 plants.

Personally i don't think the problems with your lights, i remember reading too much leaf was caused by feeding too much N, maybe you should look into your feeding routine?

Sorry at the best of times it's hard to put a number on yield but having no experience of that sort of light i really can't say.

If you've got any pics of the plants it may be of help to the more experienced grower, they may be able to spot something.

Good luck sorting it!