DE Constantly Returning Into Pool

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Hi everyone,

I have a Pentair FNS Plus 60 filter that I maintain myself. For about the past two years, I notice that whenever I refill the DE after a full cleaning that the spa become cloudy almost immediately because of all of the DE return. I used to skim the excess by hand, but now I just leave my pump on at its highest speed for several hours to "clean up" whatever has been pushed back into the pool. The problem I am facing is that I am at a point where I have to clean my filter every 2 months or so due to poor suction issues. The DE builds up at the base of my filter and turns into a wet mud consistency hindering water flow. I have replaced all of my grids, the manifold, and the air bleed assembly. The only thing I have yet to try is to reduce the amount of DE that is poured into the pool - I follow what is in the manual (6lbs) using a one pound scoop.

What is really strange is that I have been maintaining the filter myself for a while and this problem only started in the past couple of years. That said, the frequency for the need to clean the filter is definitely increasing. Is there anything else I can/should try before I start calling around for a pro?

Appreciate any help and guidance.

 

[AQUA~HOLICS]

The filter building up with DE at the bottom may be due to the way the DE is being added to the skimmer and the speed that it’s being added.

The DE getting past the grids and into the spa may be from a o-ring needing to be replaced or needing to be lubed, it’s surprising how small of a area is needed for the DE to escape from the filter and how small of a amount will look like so much more.

 

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The filter building up with DE at the bottom may be due to the way the DE is being added to the skimmer and the speed that it’s being added.

The DE getting past the grids and into the spa may be from a o-ring needing to be replaced or needing to be lubed, it’s surprising how small of a area is needed for the DE to escape from the filter and how small of a amount will look like so much more.

Thanks for your response, AH.

I have not replaced the o-ring, but I do keep it well lubricated. It won't hurt to replace it though at my next cleaning. In terms of how the DE is added, I have tried both the method of adding via a slurry using 1lb of de in a 5 gallon bucket at a time, and I have tried adding directly, both result in DE returning to the pool. I have also played with different low speeds (1800 rpm) vs high speed (3400 rpm) with no noticeable difference other than the murkiness in the spa clears up a lot more quickly with high speed vs low.

 

[1poolman1]

Thanks for your response, AH.

I have not replaced the o-ring, but I do keep it well lubricated. It won't hurt to replace it though at my next cleaning. In terms of how the DE is added, I have tried both the method of adding via a slurry using 1lb of de in a 5 gallon bucket at a time, and I have tried adding directly, both result in DE returning to the pool. I have also played with different low speeds (1800 rpm) vs high speed (3400 rpm) with no noticeable difference other than the murkiness in the spa clears up a lot more quickly with high speed vs low.

Is the air-relief screen in place? Are all grids seated properly? Are there any cracks in the manifold?