WOW.............lol..................I use to do the same damn thing....................small world, lol.
Your setup I mean. Bought ready made ones and modded them..................They were called the Greatest Growing Machine...............lol.............or something like that.
About exact setup as yours. About same # plant sites, same size PVC, different connection however, but same ability to run it as a DWC, or a Thin Film set up,
or straight top drip....
I ran 1 grow with 3 sets of them....................that was 12 years ago.............they have been in my attic since....................need to give them away I guess.........
Ran across your thread, saw your setup, just had to look and comment................Good luck with your grow!!!!