quick should i go t5

- am puting a grow closet togeather and I have a 400w. Would I benifit from using a 4 by 2 t5 setup as well. I can get one for 75 bucks.

the more the better, those should work great for sidelighting.

yes.. i was talked into getting one awhile ago, and absolutely love mine.. its great for vegging, and i even put bloom bulbs and use it along with my hps for flowering.. great investment, and a steal for seventy five bucks.. run, don't walk, to the store and pick one up is my two cents worth..

Its a closet that's 71 tall 48 long and 20 wide. I thought I'd put it on back wall inside if it will help for side growth at all and turn plants daily. Would I benifit?

yes, of course. more light=more energy=more growth.

this is exactly how i use mine.. i have it hung verically so that the whole plant is getting light, not just what gets light from the hps from above.. good stuff..