This question has been asked before, but I did not see an answer that satisfied me, so I am asking it again myself. I will provide as many details as I can.
My 16x32' vinyl inground pool was installed in 2006. The filter was exposed to the elements for one season, then I built a shed around it.
In 2008, the original EC65 assembly started leaking DE into the pool. It turned out that the little ceramic disk from the backflow preventer valve had broken off and had moved around freely in the filter housing. It had torn holes into the filter finger covers. It is likely that the installers caused this.
Either way, after doing some research, I decided to just order a complete filter as opposed to parts. It is just not worth it. I replaced the filter finger nest only and left the other original components in place (housing, connections, and cover). The filter has been working fine until last week.
By "working fine" I mean that I have been able to manage seasonal changes in water quality with minimal maintenance. I use a black "solar" cover under the mesh cover that keeps most sand and pollen out of the water until I open the pool. When I pull the cover off in early June, the water is normally blue with minimal sediment around the edges. It was no different this spring.
The pool has been open for about 4 weeks. I had the water tested twice and added chemicals as needed. The water was blue and clear when about a week ago I noticed that the pressure was high and water was barely flowing through the pump. I performed the following steps since then, with no real success:
- I backwashed and primed
- I opened the filter assembly and hosed off the fingers. They looked normal - a bit grey, but free of deposits. The flexible inserts moved freely. Put everything back together. Pressure was normal for an hour, then back to status quo.
- Talked to a guy at my pool store. He said 90% of customers with this problem have cracks in the top plates. I purchased a filter cleaner, went home, disassembled unit again and could not find any cracks. Used the cleaner, put things together, pressure was initially normal, after a couple of hours back to status quo (i.e. over 20psi and flow severely reduced)
- Called Hayward support and described the issue. The lady suggested that something must be in my water that is clogging the filter. The water is clear, though. Now of course it is getting increasingly cloudy when the pressure rises and the flow drops. After a cleaning cycle it clears up again, but I can't dedicate this much time to pool maintenance on an ongoing basis and I need a solution.
- Finally got a bottle of Muratic Acid and soaked the filter finger nest today. I removed the top plate and the rubber gasket and only soaked the fingers and the bottom plate - no metal parts. The MA that I bought at Home Depot was not as concentrated. I used 10 gallons of water with 1 gallon of MA for 2 hours. The fingers lightened up a bit but did not turn completely white.
When I reassembled everything, it occurred to me that it might be possible to misalign the top plate so that the holes are not lined up. I made sure that I assembled everything correctly. This time I replaced the old filter housing with the spare from 2008, including a new pump discharge elbow assembly. So there is now nothing left from the original unit. It has been running for about 6 hours. The pressure started at 11psi and is now up at 16psi. I don't think the problem is solved.
The filter finger fabric looks and feels like it is good condition. There are no tears, and I don't have DE leaking into the pool right now. When I shut off the pump, the pressure goes down to 0 immediately (i.e. there is no obstruction in the returns).
Once again: my pool was clear when the problem started. I have been managing my pool for 8 years and I am aware that there is a need for more frequent backwashing during the first couple of weeks after starting up for the season. This does not explain my issue. We are in the middle of the season. The pool has been running fine for several weeks with normal pressure. The only "change" was that the pool temperature finally reached 80 degrees after a particularly cold and rainy spring. I don't have algae and the water was clear. The water chemistry is fine.
I ordered another EC65 as a last resort. It came today and is sitting in the garage, but I am hesitant about what I should do. If I replace the whole filter and it works, I will not know what caused the issue, but I will be on my 3rd unit in 8 years - not exactly what you'd expect. If I replace it and the issue remains, it will have sunk $400. Neither outcome is desirable, so I'd like to get some ideas about what could be causing the issue. Could it be the pump? It seems to work fine and there is no unusual noise.