Testing a sand filter--Any ideas?
- Thread starter JohnT
- Start date
Rangeball said:
Afraid not. 5 years of trouble free service of a 1HP pump and 24" filter. The sudden onset screams freeze damage to me, but everything was drained last year and it's indoors so there wasn't any rain water getting in.
Here is a crazy idea…I think we both have the same multiport (Sta-rite wc112).
[attachment=0:138b2wxg]Picture2.png[/attachment:138b2wxg]
The picture shows the multiport with the top half removed. The detailed area shows the cavity that goes to the large riser. Filtered water comes up the riser and through this cavity before being redirected to the pool. In the bottom floor of this cavity is a small hole about 3mm in diameter. The hole goes to the unfiltered water on top of the sand. I think it is there to remove air bubbles, but who knows? If dirty water under pressure is on top of the sand, it could pass through this small hole and redirect straight to the pool, basically bypassing the sand. From what little I know, fluids take the path of least resistance. So, when pressure builds on top of the sand, a little more water and dirt would be more likely to pass through this hole than the sand. I have thought about plugging the hole to see what happens but I have other problems to figure out right now. I can take an actual picture and post it tomorrow.
[attachment=0:138b2wxg]Picture2.png[/attachment:138b2wxg]
The picture shows the multiport with the top half removed. The detailed area shows the cavity that goes to the large riser. Filtered water comes up the riser and through this cavity before being redirected to the pool. In the bottom floor of this cavity is a small hole about 3mm in diameter. The hole goes to the unfiltered water on top of the sand. I think it is there to remove air bubbles, but who knows? If dirty water under pressure is on top of the sand, it could pass through this small hole and redirect straight to the pool, basically bypassing the sand. From what little I know, fluids take the path of least resistance. So, when pressure builds on top of the sand, a little more water and dirt would be more likely to pass through this hole than the sand. I have thought about plugging the hole to see what happens but I have other problems to figure out right now. I can take an actual picture and post it tomorrow.
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Interesting that you mention that hole. I had wondered about it myself. As a matter of fact, when I first started looking at mine, it had a bug's head stuck in it. 
That hole is in the "chamber" that routes water in/out of the riser pipe, but I believe that portion is in contact with clean water on both sides if I remember correctly. I had wondered if it was there to vent air in the event the pump was turned on while the filter was in the "closed" position to avoid compressing air inside the filter.
Just a couple of other observations about my problem:
Turning the solar on adds about 2 psi to my pressure. This has no effect on the problem. I didn't expect it would, since it's added to both sides of the filter.
The filter does a fine job filtering very dirty water. I churned up the crud on the bottom of the pool near the drain to the point that the pump strainer basket was no longer visible in the housing due to the dirty water being pumped. The water coming from the returns remained clear for as long as I kept checking on it (hours).
I pulled the multiport again today and very carefully examined the riser above the sand. It is flawless. I squeezed, scraped and otherwise checked it and then wrapped it in tape with no change.
That hole is in the "chamber" that routes water in/out of the riser pipe, but I believe that portion is in contact with clean water on both sides if I remember correctly. I had wondered if it was there to vent air in the event the pump was turned on while the filter was in the "closed" position to avoid compressing air inside the filter.
Just a couple of other observations about my problem:
Turning the solar on adds about 2 psi to my pressure. This has no effect on the problem. I didn't expect it would, since it's added to both sides of the filter.
The filter does a fine job filtering very dirty water. I churned up the crud on the bottom of the pool near the drain to the point that the pump strainer basket was no longer visible in the housing due to the dirty water being pumped. The water coming from the returns remained clear for as long as I kept checking on it (hours).
I pulled the multiport again today and very carefully examined the riser above the sand. It is flawless. I squeezed, scraped and otherwise checked it and then wrapped it in tape with no change.
I think the back side of the hole goes to unfiltered water. I pushed a wire through the hole and it came out of the bottom of the multiport in the yellow/white basket where the unfiltered water is distributed across the sand. I think the back of the hole is actually visible. Try shining a light into the chamber and looking at the bottom of the valve or pushing a wire through.
It is difficult to see because of the basket type thing on the bottom. I am taking mine apart tomorrow anyway so I will double check and report back.
My filter also takes care of all large particles and looks crystal clear but will not hold back all D.E. powder. Some gets through while some doesn’t.
It is difficult to see because of the basket type thing on the bottom. I am taking mine apart tomorrow anyway so I will double check and report back.
My filter also takes care of all large particles and looks crystal clear but will not hold back all D.E. powder. Some gets through while some doesn’t.
Still begs the question, why all of a sudden?
And even bigger, this design has been around for a long time, no? Has anyone else had this issue with this filter?
And even bigger, this design has been around for a long time, no? Has anyone else had this issue with this filter?
chrisexv6 said:
It was this way upon opening this year, so I keep having the nagging thought that something didn't drain and had ice inside it over the winter.
I got up this morning and tried it with the eyeballs removed from the returns, thinking this might make the pressure differential across the filter greater and make the problem worse. It may have started a little more quickly, but not so much as to give any information.
It just occurred to me - have you seen the problem any more since the first time? If not maybe the return lines were full of algae which came out the first time you ran the pump and you don't have a filter problem after all.
JohnT said:
Are you thinking underground plumbing issues? Or just something with the filter?
Still hate to say it but you can always replace the rest of the filter. But imagine the pain if it *still* doesnt fix it.
chrisexv6 said:
I'm thinking filter. That's the only place the clean and dirty water come close together, and the dirt coming from the returns is clearly the algae from the pool bottom.
The point I'm at now is that I can replace the filter for ~$150 more than I can replace the rest of the parts. $150 to be done with it is much too tempting to replace the rest of it.
deadrabbit said:
You are correct. For those not familiar with the filter and valve, the chamber of the multport valve body that carries the flow from the riser to the valve has a ~1/8" hole in the bottom of it that goes directly to the top of the diffuser where the dirty water enters the filter.
It seems that since the incoming dirty water will be at a higher pressure than the exiting clean water that you would always have a slight flow of dirty water into the clean water. :?
Now what the devil is this hole for? Safety/air venting? Driving me crazy? If for some reason my valve to pool flow had improved drastically, could I be getting excess bleeding of dirty water through the hole? Stuck check valve on the solar?
I'm starting to babble. I was in a meeting at work this morning and found myself thinking about my filter.
My filter pressure is normal and the gauge is behaving normally. I'll try a spare gauge that I have tomorrow to be absolutely certain. Eyeballs in the pool are not new and are all installed.
I think I might just plug my hole and see what happens. I get a small amount of D.E. in the pool over a long time period after adding it to the sand. It is either passing through the sand or the small hole.
I think it is only there to bleed air from the filter. I don’t know if other systems are the same. I have seen air relief caps on Hayward and air bleeder/tee assemblies on Pentair but I don’t know if these serve the same function or not.
I think it is only there to bleed air from the filter. I don’t know if other systems are the same. I have seen air relief caps on Hayward and air bleeder/tee assemblies on Pentair but I don’t know if these serve the same function or not.
I don't have this filter, but had a similar problem.
I have a Baker Hydro filter that was passing insect shells, lawn debris, etc.. that was getting caught in my ECG screen. I took the filter apart and found that the air relief screen ( item 5 in this parts diagram - http://www.poolcenter.com/parts_filter_baker_hydro_BakerII_1984.htm ) was broken. It is just a little plastic screen that keeps "stuff" in the filter, while allowing trapped air to escape. After I replaced it, no more "stuff" in the ECG screen!
Perhaps there is some type of "screen" missing from that hole?
Can you get a new MPV to look at?
Instead of plugging the hole, I would try to attach some sort of filter screen to it, maybe a piece of Scotch brite or cheese cloth? You know, something to let the air out, but keep the "stuff" in?
Good Luck, and Best Wishes!!!
I have a Baker Hydro filter that was passing insect shells, lawn debris, etc.. that was getting caught in my ECG screen. I took the filter apart and found that the air relief screen ( item 5 in this parts diagram - http://www.poolcenter.com/parts_filter_baker_hydro_BakerII_1984.htm ) was broken. It is just a little plastic screen that keeps "stuff" in the filter, while allowing trapped air to escape. After I replaced it, no more "stuff" in the ECG screen!
Perhaps there is some type of "screen" missing from that hole?
Can you get a new MPV to look at?
Instead of plugging the hole, I would try to attach some sort of filter screen to it, maybe a piece of Scotch brite or cheese cloth? You know, something to let the air out, but keep the "stuff" in?
Good Luck, and Best Wishes!!!
Throwing this out to let everybody know that I never did figure the beast out. :grrrr: My pump failed on the morning of May26th, and I threw up my hands and ordered a new filter. I bought a Hayward S244T, and a Pentair Whisperflo WFE-4.
From the beginning, the S244T has behaved more like I expect a sand filter to work. My Sta-Rite never showed small pressure increases from dirt, although it had worked well prior to this season. It was always either 18psi or nearly 30 psi. I never once saw it at say 20 psi or any other reading in between. The day I got the Hayward filled with the same sand that was in the Sta-Rite, I came back out after a few hours and saw the gauge (old gauge off the Sta-Rite) was reading 22psi, up 2psi from my new normal 20psi. The next morning it was 26psi. I backwashed and went back to 20.
When I replumbed, I switch from a 1.5" T at the junction of my drain and skimmer line to a 2" T and pipe to the pump, since my new pump has 2" fittings. I figured there was no sense throttling it down before I had to. The better flow that I'm seeing in the pool has made a significant improvement in my skimmer performance.
The Sta-Rite is completely disassembled, and I still cannot see a flaw in it anywhere. Frustrating, but my water is clear again.
From the beginning, the S244T has behaved more like I expect a sand filter to work. My Sta-Rite never showed small pressure increases from dirt, although it had worked well prior to this season. It was always either 18psi or nearly 30 psi. I never once saw it at say 20 psi or any other reading in between. The day I got the Hayward filled with the same sand that was in the Sta-Rite, I came back out after a few hours and saw the gauge (old gauge off the Sta-Rite) was reading 22psi, up 2psi from my new normal 20psi. The next morning it was 26psi. I backwashed and went back to 20.
When I replumbed, I switch from a 1.5" T at the junction of my drain and skimmer line to a 2" T and pipe to the pump, since my new pump has 2" fittings. I figured there was no sense throttling it down before I had to. The better flow that I'm seeing in the pool has made a significant improvement in my skimmer performance.
The Sta-Rite is completely disassembled, and I still cannot see a flaw in it anywhere. Frustrating, but my water is clear again.