Quote Originally Posted by packerfan
i've come to the conclusion, now that i'm on my 3rd sand filter , that there is no way of not getting sand back into the pool. i've been through it all with a sta-rite,jacuzzi, and now hayward sand filter,and seems no matter what i do, i get sand of some type in my pool after running the filter over night. i now have the Zeobrite stuff in my new filter and have the same problem. any ideas? the reason i changed filters is i totally rebuilt them ,laterals,standpipe ,etc. and still had the problem . this is one reason maybe someday i'll go to the DE type.
OK, I've NEVER had this problem in 4 years, and I don't think Poconos has had it in 9 years. I can think of only 2 things going on:

1) It's not sand but something finer that's too fine for your sand to filter. I don't know where you live, but maybe you have some very fine dust there that's less than 60 microns. Actually, I think my NEXT cause is more likely.

2) What I REALLY think is happening is that your pump is too big for your filter. If your pump's GPM rating is higher than your filter's then it will force sand back into the pool. I was VERY careful to get a filter with a bigger capac than my pump, and I mostly run it at low speed (I have a 2 speed). I was AMAZED to find it actually filters better at low speed--seems the water at a lower velocity can allow the sand to filter more.

Why don't you post your pump size and model and your filter size and model? I'm betting you have a monster pump and it's overwhelming every filter you've had.