Sand Filter Issues

[CarlD]

Whew! A lot going on! 12 hours a day for a 5K pool? That's about 4 times longer than you need--I'd run that size filter on MY pool and it's 20k. Are you running at low speed? is that what you meant?

Now the problem is almost certainly in your multiport valve. I'm not the MPV expert but you symptoms sound like
a) A perforated or broken wall between channels in the MPV
b) A damaged and/or out-of-goove spider gasket.
c) A damaged valve mechanism.

That's what I'd check first.

[djonesax]

The water had this constant haze so I kept filtering longer and longer to try to get rid of it. I was doing 24hrs a day for a couple weeks. Wife wasn't happy about the power bill. I'll drop it down.

If I took apart the MPV would I be able to see if there were a damaged or perforated wall and is the MPV easy to take a part? The handle came off once by accident because the pin slipped out. I was able to get it back in but took some effort. I don't mind taking the entire thing apart as long as its one of those things that I can get back together by reversing the steps. I would just hate to have it apart and then need some special tool to rebuild it.

Yes the pump is on low speed at 1750 rpm. High is 3500 rpm.

David

[Poconos]

Did a Google on that filter and it looks like you can take the valve apart easily and far enough to check the internals. It looks similar to the Haywards. Put the handle in a middle position, between settings. That relieves pressure on the spider gasket so the halves won't spring apart when you next remove the 6 bolts that hold the top and main body together. The top should lift right off. Shouldn't need to take it apart further to see if the spider gasket or the valve pieces themselves are damaged.
As for the problem of the flow decreasing, I can't explain that yet. The leaking out the waste line is as Carl suggests. If that valve has a recirculate or bypass position I'd try running in that mode to see if the flow drops. This mode bypasses the filter. If the flow symptoms still occur then it's something else in the system causing the problem. Quite possibly the pump. Let us know what you find and we'll take it further.
Al

Edit: Also, what happens to the pressure reading when you switch to high speed and what's the pump rating?

[CarlD]

Al is far more knowledgeable about the multi-port valves and the workings of the pumps than I am so I'll let him take it.

I've only had my MPV apart once and never pulled apart the pump...It ain't broke so I'm not fixing it!.