I recently installed a used 26" baqapure / 200lb sand filter on small 5000 gallon pool. I have the pump set at 1750 RPM filtering 12 hours a day, and chlorine dispenser on the line running back to the pool. I really need some help figuring out some problems I am having. I have posted this on another forum but no one seemed to want to help.

Here are the issues I am having...

1. My water has this haze that I think must be sand particles floating in the water and then they settle out to the bottom because I get what looks like sand on the bottom of the pool.
2. When I change the port position on the multi-port valve the water gushes out of the backwash port. When I get it back to filter it still comes out of the back wash port just slower. I can usually get it to stop by tapping the multi-port handle with a rubber mallet. I have a hose connected to the backwash port and just have it going back into the pool so the drip doesn't create a swamp. The water that is coming out of it looks clean unless I have it on backwash.
3. I am reading between 0-5 PSI on the pressure gauge but most of the time it is 0 PSI
4. The suction on the pump seems to drop after a while and the only way for me to restore it is to change the position of the multi-valve port and then move it back to filter and the suction is strong again.
5. When I hook up the vacuum, it works well for a little while and then the suction drops. I can restore it by changing the port position like above.

I really want some help on this. I have cartridge filter system that I can use in place of the sand filter system but don’t want to swap it out unless I absolutely have to. I spent a lot of time and money wiring up this system which is 220 and the other is 110.

Thanks,

David