I understand this...but in your previous post you have 6 T's and an L for a 5 wide system....that still just doesnt add up for me. T on the far left for the column/vertical line, with the T barb leading to the line for that row, with T's on the first 4 tubs to keep the line going, bringing the total up to 5 t's for the row, plus the L on the end. I still don't see where the sixth T is coming in.
As for the in the middle/front idea, that is basically what I am asking for peoples suggestions on. I can run the vertical line with T's down the line, with the line for every row leading to an L in the middle/front to lead to the valve....or, just have the vertical line with the T lead to the valve with some slack to put it wherever I want it. The first way will keep everything straight and neat, but for a single column rack, I think it may be more hassle/cost than it may be worth. Even though it is only 1 tub wide, you still suggest the extra cost/work is worth it to have the valves in the middle/front?
If I don't do the front/middle thing, it will look more or less like what the tutorial described in nixer's link, which is my rack.