Broken multiport?

[Bigfellor]

I just pulled my multiport valve off to do a deep clean of the sand filter and when I pulled it up this piece was stuck on the stand pipe. Is this why I'm getting sand out of my filter when I back wash?

 

[Texas Splash]

Is this why I'm getting sand out of my filter when I back wash?

I don't think so. Those are typically a tight friction fit at the top of the center pipe. Probably good it was snug. As long as it's not cracked or anything, you should be able to slip it back on the pipe for a tight fit.

For sand out of the waste line, have you inspected the key way diverter and/or spider gasket of that multiport valve?

 

[Bigfellor]

I don't think so. Those are typically a tight friction fit at the top of the center pipe. Probably good it was snug. As long as it's not cracked or anything, you should be able to slip it back on the pipe for a tight fit.

For sand out of the waste line, have you inspected the key way diverter and/or spider gasket of that multiport valve?

Not yet. This was a brand new valve last year. What am I looking for?

 

[Texas Splash]

This was a brand new valve last year.

Oh, that's a bit surprising. So new, the spider gasket and internal parts should still be good.

Before we go any further assuming a part is bad, Let's confirm a few things about your backwashing. It's not unusual to see some sand make its way out the waste line when you backwash. It happens. Then when you rinse, you go until the water is clear and perhas even another 30 seconds or so before going back to filter. Also, you are turning off the pump before changing settings correct?

 

[Bigfellor]

Oh, that's a bit surprising. So new, the spider gasket and internal parts should still be good.

Before we go any further assuming a part is bad, Let's confirm a few things about your backwashing. It's not unusual to see some sand make its way out the waste line when you backwash. It happens. Then when you rinse, you go until the water is clear and perhas even another 30 seconds or so before going back to filter. Also, you are turning off the pump before changing settings correct?

Turning off the pump before changing, yes, always.

As for rinsing until clear, I'm not totally sure. I apparently have an unusual set up. My equipment is all about 15 feet from the pool in the corner near the fence. From the fence, I have PVC running down the side of the house as my drain. When I vacuum, backwash, rinse, I connect move PVC to get it out to the street. So I can't see it from where the equipment is. I usually backwash for a couple mins, then rinse for a couple mins.

 

[Bigfellor]

Oh, that's a bit surprising. So new, the spider gasket and internal parts should still be good.

Before we go any further assuming a part is bad, Let's confirm a few things about your backwashing. It's not unusual to see some sand make its way out the waste line when you backwash. It happens. Then when you rinse, you go until the water is clear and perhas even another 30 seconds or so before going back to filter. Also, you are turning off the pump before changing settings correct?

This is from the last backwash

 

[Texas Splash]

I'm going to give a shout out to @1poolman1 for his take on this. Curious what he thinks. I'm not seeing an obvious reason why you should be losing that much sand to backwash in such a relatively new system.

 

[1poolman1]

I just pulled my multiport valve off to do a deep clean of the sand filter and when I pulled it up this piece was stuck on the stand pipe. Is this why I'm getting sand out of my filter when I back wash?View attachment 636980

That's the diffuser that more evenly distributes the water in normal filter mode. All sand filters have them in one form or another. Which model filter is that. Size? Has the pump been "upgraded" to a more powerful one?
The "sand" in the picture looks very fine, almost like a powder or DE.
What sand was used? Was DE or another "filter aid" used to help clear the water? DE will always come out and look like the picture when backwashed.
How much "sand" was placed in the tank when it was filled? Overfill a tank and it will continue to spit sand during a backwash until the proper level is reached and the pump can't lift the sand into the valve.

 

[Bigfellor]

That's the diffuser that more evenly distributes the water in normal filter mode. All sand filters have them in one form or another. Which model filter is that. Size? Has the pump been "upgraded" to a more powerful one?
The "sand" in the picture looks very fine, almost like a powder or DE.
What sand was used? Was DE or another "filter aid" used to help clear the water? DE will always come out and look like the picture when backwashed.
How much "sand" was placed in the tank when it was filled? Overfill a tank and it will continue to spit sand during a backwash until the proper level is reached and the pump can't lift the sand into the valve.

It's a Water Way / Outdoor Pro 22" 200lb sand filter. I just cleaned it out completely, took out all the laterals, cleaned them as well, and put 200lb fresh sand in. That filled it to about 3/4 full. I am also getting a bunch of sand shooting back into the pool when the valve is on filter mode.

And yes, I previously had added some DE to it. As to what type of sand? "Pool sand" #20 silica I think it is.

 

[Texas Splash]

I am also getting a bunch of sand shooting back into the pool when the valve is on filter mode.

That's never good. Were you careful to fill the filter vessel with a good one foot or so of water to protect the laterals from the weight of the sand as it was poured in? I hope one of those laterals didn't snap or come loose during the fill. A fresh sand fill also requires a longer than normal initial backwash and thorough rinse to help get the sand to settle.

Not all sand is created equal either. We've heard some horror stories about some brands. Do you recall the name brand of the sand?

 

[Bigfellor]

That's never good. Were you careful to fill the filter vessel with a good one foot or so of water to protect the laterals from the weight of the sand as it was poured in? I hope one of those laterals didn't snap or come loose during the fill. A fresh sand fill also requires a longer than normal initial backwash and thorough rinse to help get the sand to settle.

Not all sand is created equal either. We've heard some horror stories about some brands. Do you recall the name brand of the sand?

Yes, I had water in before filling with sand. Even before this batch of new sand i was getting sand in the pool.

2 bags were Aquaquartz from Leslie's Pools and 2 bags were whatever Ace Hardware had in stock, don't recall the brand.


Looking inside the pool vacuum.

 

[Texas Splash]

I'll reach out to @1poolman1 for a second opinion, but if sand is coming out of the jets, only two things come to mind: Sand that is too fine (which I don't think is likely here) or the lateral assembly somehow got compromised. But let's see what PM has to say in case I'm overlooking something.

 

[Bigfellor]

I'll reach out to @1poolman1 for a second opinion, but if sand is coming out of the jets, only two things come to mind: Sand that is too fine (which I don't think is likely here) or the lateral assembly somehow got compromised. But let's see what PM has to say in case I'm overlooking something.

Sounds good, thanks for the help.

 

[1poolman1]

I'll reach out to @1poolman1 for a second opinion, but if sand is coming out of the jets, only two things come to mind: Sand that is too fine (which I don't think is likely here) or the lateral assembly somehow got compromised. But let's see what PM has to say in case I'm overlooking something.

In order for the filter sand to get into the returns, there must be something in the lateral system (including the hub and center pipe) allowing it into the center pipe that the clean water flows through in filter mode.

Usually, the only way that the valve could be responsible is if the gasket was compromised and allowed sand into the wrong (pool return) port in the valve during backwash. It would then wash into the pool when the pool started filtering again. First, that would require the sand to be lifted that high in the tank. Too much sand or too large a pump might do that, but the proper freeboard (area above the sand) usually prevents it. A proper fill amount gets you to that point, which it sounds like was done. And, the valve is new. That just leaves the lateral assembly.

The flow in all sand filters with a top-mounted valve is into the valve, down from the top, through the sand, through the lateral assembly (including the hub), up through the center pipe, into the outlet port of the valve and back to the pool. Some parts crack. Laterals wear out, the small pieces that make up the screen get broken or sometimes worn down during the backwash cycle as the sand is tumbled around. They also can crack right at the hub when the tank is filled or during use (that's where I've seen damage most times).

Unfortunately, that means the only way to determine what is wrong is to dump the sand and get back to the plumbing so it can be inspected and repaired. Lay out a tarp and save it for reuse, don't toss it.

Fortunately, a 200# filter is much easier to deal with than a larger one.

 

[Bigfellor]

In order for the filter sand to get into the returns, there must be something in the lateral system (including the hub and center pipe) allowing it into the center pipe that the clean water flows through in filter mode.

Usually, the only way that the valve could be responsible is if the gasket was compromised and allowed sand into the wrong (pool return) port in the valve during backwash. It would then wash into the pool when the pool started filtering again. First, that would require the sand to be lifted that high in the tank. Too much sand or too large a pump might do that, but the proper freeboard (area above the sand) usually prevents it. A proper fill amount gets you to that point, which it sounds like was done. And, the valve is new. That just leaves the lateral assembly.

The flow in all sand filters with a top-mounted valve is into the valve, down from the top, through the sand, through the lateral assembly (including the hub), up through the center pipe, into the outlet port of the valve and back to the pool. Some parts crack. Laterals wear out, the small pieces that make up the screen get broken or sometimes worn down during the backwash cycle as the sand is tumbled around. They also can crack right at the hub when the tank is filled or during use (that's where I've seen damage most times).

Unfortunately, that means the only way to determine what is wrong is to dump the sand and get back to the plumbing so it can be inspected and repaired. Lay out a tarp and save it for reuse, don't toss it.

Fortunately, a 200# filter is much easier to deal with than a larger one.

Thanks for all the good info. For now, it's staying the way it is.