Slow Water on Return and Backwash

[mohawk]

We have a 1 year old 21" Sta-Rite sand filter. I had a repairman out from the store this year because it was blowing sand back into the pool. He changed out some of the laterals and also took out some of the sand and said " try that and see how it works out". Well the sand problem was fixed, but after a hard rain this week I tried to lower the water by backwashing the filter but the water would only run out SLOWLY. I then tried the water going to waste and had no problem. I noticed when the filter is set to filtration that the water coming out the return is also much slower than normal. The pressure on the pump is at 20psi, which is where is normally is. The serviceman said it must be in the sand and wanted to change it out for $350.00. I told him it was hard for me to believe it was the sand, but that I would try to manually stir it up and see if that would help. It didn't. This guy doesn't seem to want to help me much if it's a warranty problem. Only if it will cost me money. Anybody have any other ideas what I might check. Thanks, Denise

[janmo]

I've been having the same problem since a storm blew through here a couple nights ago (and I had to backwash to lower the water level). The backwash dribbles and the return jets start off strong for about 30 seconds and then barely shoot any water out (and no suction to vacuum). I have checked for stuff in the lines....nothing.....and am now just letting it backwash for a long time to see if that helps. BUT, we are going on water restrictions starting Tuesday so I hate to lose any water!

Anyway, I am looking forward to any replies to your thread!
Janis

[janmo]

I hope I am not hijacking your thread, Mohawk, but wanted to add that mine is making a swooshing sound at the top of the filter...like shoosh-shoosh and it causes the pipes to shake a bit when it does this. Also, when that storm came through a large iron table was blown into the pool and it broke the drain cover so the drain has been half exposed. Could something have gotten into the drain that is causing this? I still consider myself a 'newbie' so am not sure exactly how everything works..... I just let it backwash for about 30 minutes and it hasn't helped. I think the swoosh is the problem but not sure what is causing it. Air? Debris in the sand?

Janis

[mohawk]

I had the pool store come out again and they changed out the multi-port but it didn't help the problem. Next they started to change out the sand. I was told that down next to the laterals were quarter sized sand chunks-which were impeding the water flow. They wanted to know where I had been getting my chemicals. Thankfully, their shock has been cheap this year so I could say it was from their store. These chunks had formed within a few months. Anyone have any ideas why? I've only been using chlorine. The pump works great now, I just don't want this to happen again in a few months. Denise