Why would a DE pool pump surge water for 20 minutes at 7 pounds then slow down as the pressure goes up?

Answer 1

Their are 2 reasons the first is that too much d.e. is being put in, the second reason which I think may be the problem is that the ropes inside the filter housing have become clogged not allowing water to pass thru the ropes, try putting only half as much D.E in the skimmer and see how long it runs before the pressure goes back up. If it goes back up in less than you are confortable with then the next step is to shut the filter down loose the prime and you should see a series of nuts going around the top of the filter you will need to remove these once they are removed remove the top housing, now looking down where you removed the top housing you will see a series of holes this is the clean side of the ropes where the water goes back into the pool, you need to pull this unit out of its chamberit will in all cases be somewhat heavy once you have it out you are going too see a big white mess you need to remove the heavy caked D.E from the ropes this may take some time a long screwdriver and a garden hose after the heavy material is removed you need to get a container that is deep enough to allow the ropes to soak over night in a muratic acid and water soultion this will open the poures of the ropes allowing your filter too run at a lower pressure for a longer period of time. Depending on how old the filter is this cleaning process should be done once a season to maintain the proper operating pressure this is one and only down fall of this type of filter. Ok muratic water soultion we use to use a cup to what ever we were cleaning if you want too use a half a cup to what ever size container go ahead in the morning after the ropes have soaked remove them from the container rinse them off with the garden hose and reassemble the filter and your pressure should be all right for the rest of the season. A: 80% of the above answer is wrong! The elements inside the filter tank are not called "ropes" but are called grids which sit in a manifold. The surging is most likely caused by 1> low water levels in the pool and the skimmer is sucking air. 2> you have suction leak somewhere between the pump and the pool skimmers. Check at the pump 1st for leaks. Loose pump lid. Bad lid o-ring. Loose fittings going into and out of the pump. Note: the pump is NOT the large tank - that is the filter. The loose fittings will have to be removed and new ones installed. The o-ring should be replaced with a good Teflon or silicone lube not the aqua blue grease that is still sold for pool use. You can use vaseline but it will not last long. The filter should be cleaned as some of the above answer indicates - have a professional do the job for adequate cleaning. What will you do with the used muriatic acid after you clean the "grids" - can't dump it into the pool - it is contaminated - can't dump into the sewer system or on the ground or the trash. k