Filtering issues after changing sand

Jul 2, 2013
4
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.

Observations:
- 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?
 
JohnT said:
Welcome to TFP!

The sand level and type of sand would be the first things to check.

Thanks John! The sand was bought at Leslie's Pools and based upon their recommendation, we put 250lbs into the filter. The sand comes to about 6 inches below the top of the filter. When refilling the sand the second time, he made sure to fill the sand with water to discourage air pockets.
 
Leslie's loves to do that. You can go years, if not decades, without changing sand. I recently changed mine from 1989, only because my filter failed (also 1989). Before the filter failed, it was working just fine on that old sand.

The sand should come to the point of the filter where it begins to bend in, at least that's how it works on mine.

Did you partially fill the filter with water (at least half) before adding the new sand?
 
The sand should come to the point of the filter where it begins to bend in, at least that's how it works on mine.
Yes, which is about where it is if not just a tad higher.

Did you partially fill the filter with water (at least half) before adding the new sand?
Not the first time but yes on the second time i did...figured the first time I created some channels around the outside of the filter because the sand was probably too dry in the middle but when I pulled all the sand out, i didn't really see any channels and there as definitely debris on/in the sand...bunch of ants and what not

Why did he change the sand in the first place? Was it not filtering well before the sand change?
He thought it would be a good idea :(. Leslie's told him it should be changed every 5 years. So he thought that he'd change it since he was changing the top valve.
 
Can you post photos of the top valve and piping?

Did you backwash the sand really good after you first installed it, then rinse it really good?

I would make sure 1) it's plumbed properly and 2) sand is backwashed / rinsed well. If it still doesn't seem to be working, check the spider gasket. I know it's new, but if the other things check out, I would then suspect some of the water is bypassing the filter.

It would also help if you added the pool info to your signature.
 
I wonder if this by any chance is a Hayward ProSeries filter. I've been noticing similar complaints. If anybody ever finds a definitive cause (assuming there is one) it'll help a lot of people.
It's a Hayward S220T.

Can you post photos of the top valve and piping?

Did you backwash the sand really good after you first installed it, then rinse it really good?

I would make sure 1) it's plumbed properly and 2) sand is backwashed / rinsed well. If it still doesn't seem to be working, check the spider gasket. I know it's new, but if the other things check out, I would then suspect some of the water is bypassing the filter.

It would also help if you added the pool info to your signature.

I'll get some pictures up by tomorrow morning. It has been backwashed and rinsed several times now but is there a specific length of time that it needs to be done when first changing the sand? I'll check the gaskets on the valve when we take pictures.

It sounds like he's had a filtering problem for a while. If he hasn't changed the valve seal(s), it would probably be a good time to try that.
He really didn't have troubles with the filter until he changed the top valve and sand...which was done at the same time.
 

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