Debris flowing back into pool

[presse55]

Hello,

Our 24' pool has a sand filter. Debris (dead algae, DE) flow back into the pool from the filter. Never having seen this before, I wonder whether to consider this normal or if something is wrong.

A bit of history:

• the pool came with a house we bought; we have no history of how the pool or filter were maintained by the previous owner;
  
  
• some time ago I tried to improve filtration with DE; after pouring approx. 6 cups, I noticed no change on filtration pressure, and the water returning from the filter was white-ish; a lot of the DE wound up at the bottom of the pool;
  so I stopped adding DE at about 6 cups;
  
  
• several weeks ago, we did a deep filter clean as per videos elsewhere on this site;
  no change, debris still kept coming when vacuuming the bottom;
  
  
• later on, suspecting the sand was bad, we changed it completely; after the old sand was removed, we were able to examine the standpipe and laterals which all looked normal - no cracks;
  even with the new sand, debris is still coming from the filter;
  
  
• 4 days ago, we had an algae problem, pH at 6, TA at 20, CYA at 100; so we decided to drain and refill with fresh water;
  
  
• we shocked to 10 ppm chlorine, killed the algae that was left;
  upon vacuuming the bottom, a lot of debris came out of the filter again;
  

In short, my question is: do I have a filter problem? what should we do next?

Pool status today:

• water is clear, no algae
• FC: 3.6 ppm
• CC: 0 ppm
• pH 7.6
• CYA: 21 ppm
• AT: 60 ppm

Thanks in advance!

Ron
Montreal

 

[JVTrain]

What about your pool equipment? I see your spa information in your signature, but nothing about the pool. That would be very helpful in this situation. Filter size/model, pump HP/model, etc.

 

[Richard320]

I'd look long and hard at the multiport valve. Make sure the right hoses are connected to the right port and then check the spider gasket. There's no way stuff as big as DE particles should pass through. It's not the laterals or the standpipe. That leaves the multiport or a missing Oring somewhere inside. The multiport is easier to access.

 

[presse55]

Thank you for your replies.

I have these pictures of the filter - a Jacuzzi Laser 192. For the pump, I am not at the pool now, I'll have specs for it tomorrow.
A friendly neighbor who helped early on in the season told me she occasionally changed the multiport valve position without first turning the pump off.

Filtering was fine early in the season, then this mess started happening. So, a damaged multiport spider gasket sounds like a reasonable possibility.

I'm off to search amazon/ebay for this gasket!

Thanks!

 

[JVTrain]

That inline chlorinator plumbing/position is... interesting. :???: If you're not using it, I would remove. If you do use it regularly, it would be a good idea to replumb it so that it was resting on the ground rather than suspended in there air on flex PVC. Could be just my selective OCD dissorder so take that for what you will.

After you do replace the spider gasket, it's a good idea to always only rotate the MPV handle in one direction only. Either always clockwise or always counter-clockwise. Should help the new one last longer... that and only moving it when the pump is off.