My brother recently changed the sand in his filter. After he put it back together, he noticed that the it wasn't filtering very well. So he pulled all of the sand out again to check the laterals. Everything looked fine. Re-filled again and is having the same problems.
- When you backwash, there is dirty water coming from the filter so I know it is partially working.
- Whenever he vacuums or adds DE, it looks like that majority of it flows straight back into the pool.
- After dealing with an algae bloom, he ran the filter non-stop for about 2 weeks trying to filter out the dead algae. It never did filter out and clear up the water. So he ended up turning the filter off for a couple of days and all of the particulates fell to the bottom of the pool.
Any ideas of what to do / what to check?