Intex Sand filter pump losing return flow after an hour

[Newerabs]

Hello, I have a really weird issue going on and I'm completely stumped. I have a Bestway 20 x 48 pool with a Intex 12" sand filter pump and a Intex SWG. I also have a Bestway wall mounted skimmer. I noticed about a week ago that after about half an hour my return is losing water pressure. After about an hour, nothing is coming out of the return. This is the weird part, to "fix" it, I turn off the pump for about 2 mintues and turn it back on and presto, the return water pressure is good. So I know it's nothing blocking the return. Everything was working fine up until about a week ago. I'm really stumped on this one and any guidance is appreciated.
I've attached pictures of my setup for further explanation.

 

[Texas Splash]

That little sand filter may be overwhelmed with organics. Have you performed an Overnight Chlorine Loss Test since opening? Do you have a full set of water test results you could share?

 

[Newerabs]

That little sand filter may be overwhelmed with organics. Have you performed an Overnight Chlorine Loss Test since opening? Do you have a full set of water test results you could share?

I have not. I guess what's confusing to me is after I shut off the pump for a couple minutes, it starts working fine again? If it IS organics, I just need to SLAM? But what if the pump won't run longer than an hour?

 

[Texas Splash]

If it IS organics, I just need to SLAM? But what if the pump won't run longer than an hour?

If a failed Overnight Chlorine Loss Test confirms that a heavy organic load in the filter is responsible for your loss of pressure, then once you start the SLAM Process, backwashing as needed will be part of the routine. If you have to be away from the pool for an extended period of time (work for example) and are concerned the pressure could skyrocket while away, you can place the MPV on recirculate until you return. Otherwise, it's just a monitoring process.

 

[PieterS]

I have a very similar setup to yours and agree with @Texas Splash . In my first year of pool ownership, I had the exact same question as you (it's probaby on the forum somewhere) and assumed my pump was bad. Turns out it was a water chemistry problem after all. I had to do frequent backwashes while doing a SLAM to keep the filter pressure from rising too high and restore flow to the pool outlet.

Even now, after upgrading to the next size (still Intex) pump/filter - pretty much anytime I vacuum the filter will need backwashing. Count on it being a weekly maintenance chore with these barely sufficient Intext filters!