DE Filter not working efficiently.

[uloset]

I have a Nautilus SS NS36 DE filter. It seems to be no working very well to remove dead algae. I put my pool through my opening SLAM earlier this year and as usual I run the pump on recirculate until I can pass the OCLT. Well a few days after that my pump died bought a replacement which was defective, long story short I was manual mixing the chlorine with lots and lots of brushing for a few weeks. Since the pump went so early after the SLAM the pool was dirty. but during the 2-3 weeks of manually mixing chlorine the water clarity stayed roughly the same. I finally got a working pump and SLAMed again passing the OCLT again.

So I started filtering but something just didn't seem right the water was very dirty (could see the bottom step, but not that floor). I was running the filter which should have clogged up super fast with water so dirty, but I could run it almost a full day or two before needing to backwash. I went through this process for days with only a small gain in water clarity. When vacuuming or recharging I've witnessed nothing returning to the pool (even had someone stand right in-front of the swallow end return while charging to double check).

Finally in frustration I grabbed an old bottle of clarifier I had and added the recommended amount. I added it late yesterday afternoon to a light green colored pool that I could barely make out the shallow end floor. By this morning the pool was total blue and I could see all the way to the deep end floor (8 feet).

Historically I was able to clear the pool in a day or 2 just using the filter with no clarifier after a SLAM even with extremely dirty water. I did switch to a cellulose fiber a few years back, but the pool has stayed very clear using. The filter pressure has remained the same as always 12ish after a backwash and 13.5-14ish after a charge. Any thoughts on what could be causing the issue?

 

[1poolman1]

I have a Nautilus SS NS36 DE filter. It seems to be no working very well to remove dead algae. I put my pool through my opening SLAM earlier this year and as usual I run the pump on recirculate until I can pass the OCLT. Well a few days after that my pump died bought a replacement which was defective, long story short I was manual mixing the chlorine with lots and lots of brushing for a few weeks. Since the pump went so early after the SLAM the pool was dirty. but during the 2-3 weeks of manually mixing chlorine the water clarity stayed roughly the same. I finally got a working pump and SLAMed again passing the OCLT again.

So I started filtering but something just didn't seem right the water was very dirty (could see the bottom step, but not that floor). I was running the filter which should have clogged up super fast with water so dirty, but I could run it almost a full day or two before needing to backwash. I went through this process for days with only a small gain in water clarity. When vacuuming or recharging I've witnessed nothing returning to the pool (even had someone stand right in-front of the swallow end return while charging to double check).

Finally in frustration I grabbed an old bottle of clarifier I had and added the recommended amount. I added it late yesterday afternoon to a light green colored pool that I could barely make out the shallow end floor. By this morning the pool was total blue and I could see all the way to the deep end floor (8 feet).

Historically I was able to clear the pool in a day or 2 just using the filter with no clarifier after a SLAM even with extremely dirty water. I did switch to a cellulose fiber a few years back, but the pool has stayed very clear using. The filter pressure has remained the same as always 12ish after a backwash and 13.5-14ish after a charge. Any thoughts on what could be causing the issue?

Is your air relief screen in place?

 

[uloset]

Is your air relief screen in place?

I'll have to pop the top and give it a look. Though I'd imagine it is in place/not blocked as the air bleeder is functioning normally.

 

[VinnyinNJ]

What is the return flow like? With my AG DE filter - 1 in, 1 out, no valves in between and no recirculate; I knew when to bump or recharge the filter based on the output ... in all the years I had the filter the gauge never went up much. Maybe too much or dirty media. I once recharged my filter with too much media and I needed to open it up and clean it out to get the filter working correctly.

Are you sure the pump is running correctly? Basket is not full of stuff? Does it recirculate fine and not when it is in filter mode? Maybe valve to recirculate didn't point to filter (don't know IG setups) or if it did the valve didn't open toward the filter. Could there be a clog somewhere between the filter and pump?

I know AG is much different then IG but that's how I would troubleshoot the issue. I would try to isolate if recirc is fine and filter is not. Then if one works and the other doesn't follow from the pump to the filter to the end or at least as much as you can. Maybe open up unions to see if you get flow to eliminate areas assuming you have unions. If your filter is similar to mine with grids it is a fairly simple design.

 

[1poolman1]

I'll have to pop the top and give it a look. Though I'd imagine it is in place/not blocked as the air bleeder is functioning normally.

Air relief screen is the small screen that should be atop the air-relief tube that should be inside the filter to allow air to escape while keeping DE and debris in the tank. Has nothing to do with the air bleed screw/valve.

 

[uloset]

Air relief screen is the small screen that should be atop the air-relief tube that should be inside the filter to allow air to escape while keeping DE and debris in the tank. Has nothing to do with the air bleed screw/valve.

I didn't have a chance to open up the filter, but wouldn't I have dirt/cellulose coming from the returns if the air relief screen was missing or ajar?

 

[uloset]

What is the return flow like? With my AG DE filter - 1 in, 1 out, no valves in between and no recirculate; I knew when to bump or recharge the filter based on the output ... in all the years I had the filter the gauge never went up much. Maybe too much or dirty media. I once recharged my filter with too much media and I needed to open it up and clean it out to get the filter working correctly.

Are you sure the pump is running correctly? Basket is not full of stuff? Does it recirculate fine and not when it is in filter mode? Maybe valve to recirculate didn't point to filter (don't know IG setups) or if it did the valve didn't open toward the filter. Could there be a clog somewhere between the filter and pump?

I know AG is much different then IG but that's how I would troubleshoot the issue. I would try to isolate if recirc is fine and filter is not. Then if one works and the other doesn't follow from the pump to the filter to the end or at least as much as you can. Maybe open up unions to see if you get flow to eliminate areas assuming you have unions. If your filter is similar to mine with grids it is a fairly simple design.

The return flow is normal, stronger when first charged and slowly diminishes as the pressure increases. It also all works fine on recirculate just moves more water at an given RPM since there is less head pressure.

 

[VinnyinNJ]

The return flow is normal, stronger when first charged and slowly diminishes as the pressure increases. It also all works fine on recirculate just moves more water at an given RPM since there is less head pressure.

I think your filter is almost identical to my Star 50 filter - 4 grids that are sandwiched in place by 2 plastic "X"s which have 2 long bolts to hold them together. Top "X" is designed for water flow. The grids sit on a white shaft with an oring on top. Mine had a knob to bump it on top of the filter housing.

If my filter sucked in air it would blow out the return but it sat 6 feet of hose length away. I could get the air out by the top air release until water shot out. If it is air you can try that, if for some reason the pump was sucking in air (using suction side cleaner) I would leave the air valve open just a bit to see water dribbling out. I only noticed the filter doing as you say when it got full of debris, could even be unseen debris. I would bump it, it may or may not get better and I knew when to recharge it.

To me and I'm no expert it sounds that your grids are getting clogged and stopping the water flow. Or is there too much media in the filter, I had that happen once on a mistake on recharging it. Old grids? That "X" getting clogged somehow.

 

[uloset]

To me and I'm no expert it sounds that your grids are getting clogged and stopping the water flow. Or is there too much media in the filter, I had that happen once on a mistake on recharging it. Old grids? That "X" getting clogged somehow.

I think you might be misunderstanding my problem. In the past if my pool water was basically a dead swamp the filter would clog up in with debris in a very short amount of time. It would take quite a few backwash recharge cycles, but I could clear the pool in in a few days max. This time around I filtered for weeks with barley a change in water clarity and the filter would take forever until the pressure raised/flow reduced. The only way I finally was able to clear it was by using a clarifier that basically binds small particles together into larger ones. So, it seems that the filter is not catching very small particles which DE filter are basically known for.

 

[VinnyinNJ]

Sorry for my misunderstanding! I was imagining that the filter starts off strong and then loses flow.

I would open the filter and see if everything is hooked up properly or if anything is missing as someone else said. I lost filtering capability once my grids started to deteriorate. If your filter has orings make sure they are OK.

I don't know the valving of IG pools but is it possible the valve is not working as it should?

Sorry I can't be of more help!

 

[1poolman1]

I didn't have a chance to open up the filter, but wouldn't I have dirt/cellulose coming from the returns if the air relief screen was missing or ajar?

If your pool isn't clearing as fast as it used to, you could be passing dirt through the tube. It would basically be a 1/4" hole in the filter. Just something to look for.

 

[uloset]

Sorry for my misunderstanding! I was imagining that the filter starts off strong and then loses flow.

I would open the filter and see if everything is hooked up properly or if anything is missing as someone else said. I lost filtering capability once my grids started to deteriorate. If your filter has orings make sure they are OK.

I don't know the valving of IG pools but is it possible the valve is not working as it should?

Sorry I can't be of more help!

Don't be sorry I appreciate any help I can get. As far as valving goes all I have pressure side is the multiport which seems to be functioning properly. When you grids started to deteriorate did you have a harder time clearing the pool or was the problem the fitler just clogged up quicker?

If your pool isn't clearing as fast as it used to, you could be passing dirt through the tube. It would basically be. a 1/4" hoke in the filter. Just something to look for.

I know the part you are talking about it a half sphere screen at the top of the manifold. It was present and attached last year when I broke it down, though I do store it in the shed every year so perhaps something came ajar while moving it. Though I am having no blow through as I had someone stand right in front of the jets during a recharge and no powder was entering the pool. I also vacuumed all the fallen dead algae the other day and had only clean water coming from the jets.

 

[VinnyinNJ]

Don't be sorry I appreciate any help I can get. As far as valving goes all I have pressure side is the multiport which seems to be functioning properly. When you grids started to deteriorate did you have a harder time clearing the pool or was the problem the fitler just clogged up quicker?


I know the part you are talking about it a half sphere screen at the top of the manifold. It was present and attached last year when I broke it down, though I do store it in the shed every year so perhaps something came ajar while moving it. Though I am having no blow through as I had someone stand right in front of the jets during a recharge and no powder was entering the pool. I also vacuumed all the fallen dead algae the other day and had only clean water coming from the jets.

If I remember correctly it just wasn't cleaning right but that was like 5 or so years ago ... things start to fade! I remembered opening up the filter at the end of the season and there were tears in the grid but 3 months before the grid looked OK. At that point the filter was about 17 YO and they were the original grids.

 

[uloset]

Well I pulled the grid assembly out yesterday the air relief screen was in place, but caked up with cellulose, though I didn't not backwash before breaking it down. I hosed all the grids and the air relief screen clean lubed the o-ring and put everything back together. The water was cleanish since using the clarifier, I could just make things out at the bottom of the deep end. I ran the pump at around 1800rpm all night and now can clearly see the liner design at the 8 feet deep.

I'm not sure if the cleaning is what helped or perhaps the manifold wasn't seated correctly on the upper pipe or a combination of the two. Either way it seems to be working again thanks again for all the feedback.