Veg grow box T5 question

[IKE]

its 4' long x 2' wide x 5' height
It will hold a mother plant - 6 clones and 2 plants in veg state.
I was gonna get an 8 bulb four feet T5 w/40K lumens but I'm not so sure i need that many lumens for a mother and the clones and a couple of plants. I understand the more lumens the better idea but what size would you get? I have a separate grow box with a 400watt HPS for bloom cycle.

 

[WoodyPheonix]

Your space is 8sq ft, at 3k lumens per sq ft, your min requirement is 24k lumens. Obviously more is better, especially for your vegging plants.
On the down side, I do not like mothers kept under T5's. The growth is so tight, it makes the cuttings very short. Also, while cuttings root, they do not need lots of light for the first 5 days/week.
In all honesty, if you are looking to just have 2 plants vegging and no more, I would look to split the space, a smaller, 2', 4 tube T5's for the true vegging plants and perhaps a few cfl's for the clones and mothers.
Just a suggestion. W

 

[The Hemp Goddess]

I have a 2 x 4 x 4' closet that I am lighting with a 4' 4 tube T5. I have considered getting a 4' 2 tube to supplement the fixture I have as it is 20,000 lumens, but I am quite happy with the growth I am getting now, even though I'm slightly underlit.

 

[Hushpuppy]

I use an 8 tube 4' T5 over my mom/clone area without any problems. My fixture has 2 switches that allow the bulbs to be controlled with 4 bulbs independant from the other 4 bulbs. I can't swear that all of the fixtures are setup like that, but if yer running both moms and clones in the same space then the light will have to be up higher to accomodate the moms, this will give less lumens for the clones anyway(which is what they want). As they grow and reach for the light, they will get more as they are getting closer to the light. I would stick with the 8 bulb, if nothing else, yu can take out a couple of the bulbs without causing any problems on most fixtures that I have seen.