Hi, i am looking after a pool and have noticed that when i vacuum the pool, all is fine, until i turn off the pump to empty the pump basket and turn it back on, a ton of dirt goes into the pool from the return jets. This does not happen whilst vacuuming.
I opened up the sand filter and the sand is new and loose as you'd expect. When I perform a backwash though i do notice that we lose some sand??
Any ideas on what could be causing this? to recap, when i clean the pool, its all ok, until i turn off the pump for a few minutes, when it goes back on, a load of dirt re-enters the pool?