would love to get some help as this is all new (and very frustrating!) to me. opened my in-ground vinyl pool for the season. noticed a ton of sand in the pool - had company over to replace valve and sand in my filter. sand still coming into pool. company came back did a thorough backwash and all seemed well for about a week. come out one morning to see pool had lost about an inch of water. did some testing, determined loss happening when pump was running, so shut pump off and called someone to come pressure test the lines. While waiting for that to happen, pool cleaners come and clean pool and turn pump back on. As soon as I notice I run out and shut it off only to find that there is SAND IN THE POOL AGAIN.
My fear/suspicion is that these two things are related, but I can't figure out how. There is no noticeable leak around the equipment, in the backwash line, etc. Am I just dealing with the world's worst luck and have two separate issues or is there some way that a malfunctioning filter could be causing an "invisible" water loss while also throwing sand back into the pool through the return lines?
Sorry if any of this is totally idiotic i know very, very little about pools.
My fear/suspicion is that these two things are related, but I can't figure out how. There is no noticeable leak around the equipment, in the backwash line, etc. Am I just dealing with the world's worst luck and have two separate issues or is there some way that a malfunctioning filter could be causing an "invisible" water loss while also throwing sand back into the pool through the return lines?
Sorry if any of this is totally idiotic i know very, very little about pools.
So let's talk about sand in the pool. Usually this happens because of a damaged lateral, center stand-pipe, or connection in the filter. This can also happen to new laterals or center pipes if someone who replaced sand didn't fill the vessel partially with water before dumping the (new) heavy sand onto those items. To inspect the laterals or center pipe one has to remove the sand, then remove all the parts and inspect. Sometimes a bad multiport valve can cause issues, but you said yours was replaced, so that would point to the laterals or center pipe inside the filter.