Sand in an above ground pool

[Grange]

Last year, I noticed a small amount of sand in my above ground pool. This spring, I changed the sand (the correct amount of 200lbs) and I installed a used lateral from a neighbor who had just taken down his pool and had given me all his equipment for spare parts. Within a week, I noticed even more sand in the pool than last year. In June, I purchased a new lateral and removed all the sand. I correctly placed the new lateral in the middle of the filter, covered it correctly with Gorilla tape. Added 1/4 of the filter with water and then put all of that used sand back into the filter. I now have just as much sand as I did in the Spring. My local pool place said they won't return the lateral because I must have done something wrong when I changed it out. I am not going to do this for the 3rd time in one year. It's about 95 degrees here now and will stay that way until September. I am not going to fight this in this heat. My question is this, can I put pantyhose or anything else over the return for the remainder of the year? We normally close up on Labor Day. I just need a quick fix for the remainder of the year. I can't keep vacuuming to waste..I'm literally throwing $$$ out the door everytime I do that in chemicals and water.

[Teapot]

Yes you can use pantyhose, just remember to take them off first lol.

[Teapot]

You don't need to vacuum to waste, just vacuum and the sand will go back into the filter. Small filters and big pumps are normal for some even this is bad for filtration and the electric bills. That means sand can be ejected during backwash. That can build up in the multiport valve and be put back into the pool. Another possibility is the spider gasket may have aged/broken and that can also lead to sand in the pool.

[Grange]

Several people have mentioned the "spider gasket" in the multiport..I have asked 3 local pool places about that and they looked at me like I had two heads and laughed at me...I hardly backwash.. this happens during filtering. I did replace my pump this year....but I replaced it with the exact same model as before. Hayward MaxFlow or something like that...it was the exact same pump. I do have access to a used Hayward Multiport... I was going to change it out before this heat wave but most people told me that it had nothing to do with sand going back to the pool.

[Teapot]

Please understand we are trying to diagnose via a PC.
Leaving out the backwash scenario. Is there an air bleed pipe from the lateral hub to the diffuser at the top. If that pipe gets missed or split it will leak sand.
With a multi port the flow of water is via chambers in the valve if the seal is damaged or broken then water can flow where it shouldn't and sometimes that can push sand out.

On my own pool my backwash seal was damaged and water went straight out the waste pipe without backwashing the glass, found only by accident and explained why some pine needles were not ejected via backwash.