One more thing. I saw on Pinterest that someone used a 5gallon bucket with the fiber stuffing like I use. Hose in one side and holes at the bottom for a larger pool. that may be an easier choice. You can change the stuffing as needed. (could be alot cheaper also)
The only thing I can say is try it, but make it where it would be easy to make adjustments if needed until you find something that works.
Also do you test your water. What are the # there. That may help with solving the problem.
I don’t know anything about sand filters to answer for sure, but IMO if the PVC is large enough and your pump is made for a pool that large it should move enough water. As for air tight that depends on how you are doing it. If it is under water I would make it so the sand can’t get into your...
I replaced the other filter with this... works so much better. For Greek try magic eraser in the debris basket... also check out Pinterest it has awesome diy ideas that work.
Not sure how it well it will work for something like this. But for our pool it’s one of those index ones. Instead of those tiny filters I use a Hawaiian Punch jug with craft filler (fiber filler). Put holes in the bottom of the jug, stuff it will the filler, connect the hose that is coming out...