I was thinking of closing off the Intex intake and adding two evenly spaced Hayward eyeball intakes at the end of the pool nearest the blue building you see in the photo, with the pump next to that building. (Near the power supply.) That way the pool flow would travel the length of the pool toward the skimmer. Any thoughts?
So I am using all 3 of the old suction side and return but 1 of them is a suctions side for a vacuum.. it works great when I need it.. I think a return on the end would work great
cowboycasey: I ordered some additional Hayward SP1023G returns which I plan to install on the end of the pool farthest from our skimmer once they arrive - 2 evenly spaced apart. I also plan to replace the old Intex "Hydroaeration" return with a Hayward SP1023G as well, just so everything is compatible. I'll close that one off for the time being, but then it will be available for use with a waterfall or other aeration device if needed later. I'm not sure if 3 returns matched to 2 suction side inlets (1 Hayward skimmer and one Hayward intake) would be in sufficient balance? (Will it really matter for such a small pool?)
BTW, we set up a simple resistance swim band rig last year for my wife so she could swim in place, with a simple PVC pipe set-up and a $25 bungie type swim belt off Amazon. With 2 return jets at one end of the pool, that should give her some added resistance!

Not exactly an endless pool, but a heck of a lot less expensive!
Also, I'm installing cut-off valves on each return, because I was planning on running them all into one return line back to the pump just to keep the total amount of plumbing to a minimum. Any reason why I would want to run each line separately and combine them just before they enter the pump? That seems like it would just create more head? (However, from your build pictures, it appears that's what you did. Any reason why?)
FYI, in reference to all discussion regarding CT-Steven's plumbing issues, all my PVC is schedule 40.
I also ordered both 3/4" and 1" eyeballs for the returns to experiment with that to see what works better. I've read a ton of info on TFP on head, flow and plumbing calculations, eyeball sizes, etc., but honestly, it's out of my depth, pun intended. I'm more or less winging it here.
Any further words of wisdom appreciated.
(I can open a new thread just for my plumping questions if need be. I certainly don't mean to put the onus on you for all advice, but really appreciate all given thus far.)