Ok here is what it looks like on the rack that has watering system on 3 rows (2 tubs wide 3 tubs hight) – Again first column is what is alimenting each row the other connectors are for each tubs on the row.
T T L
T T L
L T L
In red the T in blue the L




For a column rack you can use onlythe T's however I like to put my valves in the middle and on the front, having the lines tied on the wood not getting in the way as shown in the previous pic.