DE returning to pool

[NYED]

I have read posts on this forum in the past that have been very helpful. After opening the pool a few weeks ago, I noticed DE on the bottom of the pool. I replaced the spider gasket on the multi-port valve that had been worn and thought that would correct the problem. I also replaced the grids and top manifold in the filter a few days ago and realized this morning, DE is still returning to the pool. So, I opened the filter and was inspecting it and noticed as the filter was open, the water drained out. There are no leaks on the outside of the filter and I am assuming the water returned to the pool. If the water is returning to the pool, I am sure the DE must be as well. Can someone tell me what would cause this problem and how I could correct this? I have owned and maintained my pool for the past eighteen years and have not experienced a problem like this. Any suggestions/recommendation would be greatly appreciated.

Thanks

 

[Cyric]

Check your pumps PSI

 

[NYED]

Pump PSI is 18 which is normal.

 

[Diver]

if multiport is in filter position and all valves on all lines are open then the water will be siphoned off the filter until level reaches the intake pipe in the filter. which is right next to the bottom of the filter.

DE coming back to pool either means a tear in the grid or bad seal between the manifold and return pipe in the filter. there is an o-ring on top of the pipe. also there could be a gap between grid pipes and manifold.

can't think of anything else.

 

[NYED]

Grids are new. I replaced the spider gasket and an o-ring in the multi-port valve. The o-ring on the standpipe is good as well. There appears to be air in the system causing my issue of DE returning into the pool. When the filter is running, I noticed there is air in the pump basket. Air does come out of the bleeder valve, but there is still an air pocket in the pump basket. Can this have anything to do with the DE returning into the pool?

 

[zea3]

No, an air bubble in the pump strainer pot indicates a suction side air leak, but should not have anything to do with DE coming out of the returns.
Looking first at the usual suspects...
Do you rinse well after back washing?
Do you turn off the pump before changing the settings on the multi-port valve?
Make sure all the grids are seated correctly in the filter?

 

[NYED]

I checked all of the grids and they are seated properly. Yes, I do rinse well after backwashing and turn the filter off prior to change the settings on the multi-port valve. When I turned the filter off and opened it to inspect the grids, the water drained out. I believe the water returned to the pool. My valve is set 100% on skimmers ( 0% Main drain) and I can see DE in the skimmer and it was not in there while the filter was running. Another reason I believe the DE is entering the pool thru the skimmers, the pool water is gritty and the waterline on the sides of the pool appear to have a DE residue. Is anyone aware of a condition that would cause this?

 

[zea3]

Could you please post a current set of test results? I would like to see if the water chemistry is part of the problem.

 

[NYED]

I have tested the water chemistry and everything appears to be within the proper ranges. The results are as follows:

Total Hardness between 250 and 500 ppm
Total Chlorine 3 ppm
Free Chlorine between the 1 and 3 ppm range
PH between 7.2 and 7.8
Total Alkalinity between 80 and 120 ppm

 

[mytidbitz]

Hi NYED. We are having the same problem with DE in the pool and air in our pump basket. When running the skimmer line only we get alot of DE sediment in the pool, but very little / almost none DE when we are running the main drains only. We've checked everything as far as the eyes can see with regards to the grids, seals, etc. Like you, we also have air in our pump basket which we believe is the reason our returns are spurting. They don't spurt when we only use the main lines. At this point we believe we may have a cracked / broken skimmer line which is underground

Do you think a broken skimmer line would be the cause of your problem as well as ours since we had such a harsh winter? (We are in NJ)
Hope we both get some answers to our DE problem so we can enjoy our pool for what is left of the summer.

 

[JohnT]

Grids are new. I replaced the spider gasket and an o-ring in the multi-port valve. The o-ring on the standpipe is good as well. There appears to be air in the system causing my issue of DE returning into the pool. When the filter is running, I noticed there is air in the pump basket. Air does come out of the bleeder valve, but there is still an air pocket in the pump basket. Can this have anything to do with the DE returning into the pool?

When you have an air leak, the air in the filter is compressed. When the pump shuts off, the air expands and forces water to run backwards through the skimmer and drain, carrying DE with it. Fix your air leak and you will fix the DE problem.

 

[NYED]

It has been very difficult finding the source of the air leak. How would I test the skimmer lines for a leak. Also, if the skimmer was the location of my leak, wouldn't I be losing water as well? The pool seems to be holding the water, with out any signs of a water leak.

 

[JohnT]

It has been very difficult finding the source of the air leak. How would I test the skimmer lines for a leak. Also, if the skimmer was the location of my leak, wouldn't I be losing water as well? The pool seems to be holding the water, with out any signs of a water leak.

An air leak often doesn't leak any water.

 

[zea3]

Airleaks occur on the suction side of the plumbing, usually where two or more pipes join together above ground, the drain plug on the pump strainer pot, or the lid on the pump strainer pot. You can check the pipe joints by either drizzling water on the joints while the pump is running or putting shaving cream on the joints with the pump running. Watch for the water or shaving cream to get sucked into the pipe along the seam to identify the leak. Make sure the pump pot drain plug is snug, check the pot lid o-ring for damage or wear, make sure it is seated completely within the groove and lube it with silicon pool lube to help get a good seal.

 

[NYED]

I did check the drain plugs and the lid on the pump strainer pot. I have two drain plugs on the pump. I removed, lubed and reset them. They are snug and do seam to be the source of my leak. seal. I will have to check the pipe joints, while the pump is running. Thanks.

 

[jmrussell18]

I am also seeing DE enter my pool after adding to the skimmer. I see it pass through the pump and then right to the return in the deep end of my pool. I purchased and installed an entire new Grid for my Hayward 6020 filter and also replaced the o-ring. I also replaced the multi-port valve this morning. So I'm ruling out a tear in the grid, a crack in the manifold, a leak in the multi-port or a leak where the o-ring meets.

I'm left wondering if it could be the return pipe inside the filter. Although I've disassembled and inspected up close, it's the last piece inside the Hayward filter which has yet to be replaced.

Do you have any other thoughts? A few years back, we converted to Salt and we also replaced the pump to a Pentair SuperFlo 1.5HP pump - is there any chance that the pump is too powerful causing the DE to flow back into pool?

Anything??