DE not coating grids, it’s filling them up!

[peterjordan]

Has anyone experienced this problem before? It’s got me baffled. Grids are relatively new, manifold has no leaks.

 

[ajw22]

Welcome to TFP.

What model filter are we discussing?

How can you tell how the DE is laying in the filter?

Are you filling it with the proper amount of DE?

Are you using pool grade DE?

 

[peterjordan]

Welcome to TFP.

What model filter are we discussing?

How can you tell how the DE is laying in the filter?

Are you filling it with the proper amount of DE?

Are you using pool grade DE?

Hello — thanks for the reply. The filter is a Nautilus NS-24.

My first indication that something was wrong was when I tried to backwash — and nothing came out. After removing the lid from the filter, I could see that the DE had completely filled the cavities of the grids! Bizarre. At least 4 times last season I dismantled the grids, cleaned them out, and restarted with clean DE.

Yes, it’s DE for pools and I’m using the proper amount.

FYI — I’ve been using this filter for 25+ years with no issues. The grids are less than 2 yrs old — no rips or tears. No leaks anywhere. No DE coming back into the pool.

Thanks.

 

[ajw22]

Next time you open up the filter take some pics of the grids and what you find and post them.

Maybe @1poolman1 @Pool_Medic @ferretbone may have ideas.

 

[Jimrahbe]

Peter,

Have you done any recent work on your Multiport valve??

The only way DE is going to get inside all the grids is for water to come in on the wrong port.

Thanks,

Jim R.

 

[peterjordan]

Next time you open up the filter take some pics of the grids and what you find and post them.

Maybe @1poolman1 @Pool_Medic @ferretbone may have ideas.

Thanks — will do. I’m taking the pump and filter out of winter storage this week. Will likely set up everything next week. Fingers crossed.

 

[peterjordan]

Peter,

Have you done any recent work on your Multiport valve??

The only way DE is going to get inside all the grids is for water to come in on the wrong port.

Thanks,

Jim R.

Hi Jim,

Funny you should ask that … yes! I’ve replaced the O-rings on the slide valve. I’m suspicious of this part too, but everything looks ok. Btw — it’s just a two position valve. Down is position is “normal” — up position is to backwash.

Any ideas are appreciated!

 

[peterjordan]

Thanks — will do. I’m taking the pump and filter out of winter storage this week. Will likely set up everything next week. Fingers crossed.

 

[peterjordan]

I think I’ve figured this out, thanks to your advice: looks as though there’s a missing cotter pin on the stem for the slide valve? See photos.

 

[Jimrahbe]

Peter,

I have never seen the inside of a push/pull valve before, but it makes sense that something has to hold the "sliders" in place. Looks like some kind of snap ring.

Thanks for the pics,

Jim R.

 

[peterjordan]

Peter,

I have never seen the inside of a push/pull valve before, but it makes sense that something has to hold the "sliders" in place. Looks like some kind of snap ring.

Thanks for the pics,

Jim R.

Hi Jim,

Turns out I had an extra slide valve around; I bought a new one a few years back and was bummed that it was all plastic. So instead, I just took the new orings off the plastic valve and installed them on the old steel valve. That must’ve been where the snap ring got lost. I’ve got it assembled now and hope to test it next week when I do the start-up.

Anyway, I’m really happy I joined this forum! I was baffled by this issue. Pool stores of course recommend anything that results in a sale: “you need new grids,” “you need new manifolds,” etc.

 

[Oly]

Anyway, I’m really happy I joined this forum! I was baffled by this issue. Pool stores of course recommend anything that results in a sale: “you need new grids,” “you need new manifolds,” etc.

Everytime we read something like this an angel gets their wings.
Become a supporting member and pay it forward. Become a TFP Supporter

 

[peterjordan]

Hi Jim,

Turns out I had an extra slide valve around; I bought a new one a few years back and was bummed that it was all plastic. So instead, I just took the new orings off the plastic valve and installed them on the old steel valve. That must’ve been where the snap ring got lost. I’ve got it assembled now and hope to test it next week when I do the start-up.

Anyway, I’m really happy I joined this forum! I was baffled by this issue. Pool stores of course recommend anything that results in a sale: “you need new grids,” “you need new manifolds,” etc.

To my frustration and dismay, I’m still having this problem, despite swapping out a new push/pull valve. DE is not coating the grids — it’s filling the cavities still. First indicator is when I try to bump or backwash — nothing comes out the waste line. If I had to guess, it’s almost as if the filter is backwashing into itself.

I pulled all the grids out, washed all the dE out from the cavities, and cleaned all the grids again. This time I’m gonna run the filter without DE for a while — the pool is clean now so it’s probably ok. I’ll try backwashing with no DE and see what happens. This is really driving me nuts

 

[Jimrahbe]

Peter,

Just so that I understand.. The DE that you are adding is going inside the grids? Is that correct?

And your grids look like this... FiltersFast FF-0531, 36 Sq Ft DE Filter Grid Set

If the above is true, I suggest that you leave the grids out and the top off the filter. And then just turn the pump on and off quickly and see which ports the water comes out of. Obviously, when in the filter mode the water should be flowing in on the "Input" pipe. And when in the backwash mode, the water should be flowing in on the "output" pipe.

I still can't see anything inside the filter causing this. Maybe if the stand pipe was ruptured, but that should be pretty obvious.

Thanks,

Jim R.

 

[peterjordan]

Peter,

Just so that I understand.. The DE that you are adding is going inside the grids? Is that correct?

And your grids look like this... FiltersFast FF-0531, 36 Sq Ft DE Filter Grid Set

If the above is true, I suggest that you leave the grids out and the top off the filter. And then just turn the pump on and off quickly and see which ports the water comes out of. Obviously, when in the filter mode the water should be flowing in on the "Input" pipe. And when in the backwash mode, the water should be flowing in on the "output" pipe.

I still can't see anything inside the filter causing this. Maybe if the stand pipe was ruptured, but that should be pretty obvious.

Thanks,

Jim R.

Hi Jim,

Yes, the DE is filling up the inside of the grids — the same ones you reference.

Before I reinstalled the clean grids, I filled the tank with water and then pulled up on the valve to backwash mode. The water drained out the backwash. Next I reinstalled the grids and started the filter. Everything seemed perfect. So I tested the backwash. Nothing — not a drop came out the backwash line.

Your suggestion makes sense. I’ll try it after I take the darned thing apart again.

I took photos of everything but they don’t really add much to the story.

 

[peterjordan]

Hi Jim,

Yes, the DE is filling up the inside of the grids — the same ones you reference.

Before I reinstalled the clean grids, I filled the tank with water and then pulled up on the valve to backwash mode. The water drained out the backwash. Next I reinstalled the grids and started the filter. Everything seemed perfect. So I tested the backwash. Nothing — not a drop came out the backwash line.

Your suggestion makes sense. I’ll try it after I take the darned thing apart again.

I took photos of everything but they don’t really add much to the story.

Ugh. I just looked at the manual for the slide valve. From the diagram in the manual, it seems I have the lines plumbed Rear backwards. That would mean that It’s been wrong all last season. I’ll post some photos — someone please comment if you can make sense of it.

 

[Jimrahbe]

Peter,

I have no experience with push pull valves, so please show me a pic with the handle all the way up and another pic the handle down.

Thanks,

Jim R.

 

[ajw22]

I’ll post some photos — someone please comment if you can make sense of it.

Yup, you have things backward.

Top pipe goes to the pool.

Middle pipe goes to the pump.

Bottom pipe is waste.

 

[peterjordan]

Yup, you have things backward.

Top pipe goes to the pool.

Middle pipe goes to the pump.

Bottom pipe is waste.

What an idiot I am! But now it makes sense: last season I replumbed everything when I added a salt generator. So last season I had it wrong. But somehow the filter still pumps and recirculates the water — the water was crystal clear even though it was plumbed backwards

 

[Jimrahbe]

Peter,

I am not sure it is backwards or if you are just moving the handle the wrong direction.

To know for sure, you need to know which filter port is the input and which is the output.

Are the filter ports labeled as input and output?

Thanks,

Jim R.