Cartridge Filter Problems

Cartridge filters can be difficult to troubleshoot.  They are more prone to allowing dirt to bypass the
filter and the exact location can be hard to detect. 

Problem:  Bad Cartridges or other Internals

Symptom:  Debris Returning to the Pool

If one of the parts inside the cartridge filter goes bad, it is
immediately obvious because dirt will be returning to the pool.  Unfortunately, the source of the problem is not so obvious.  In a 400 square foot
pleated cartridge, it can be difficult to pinpoint the source of problem.

There are several problem areas that can cause dirt to return to the pool:

Torn Filter Material – these are usually pretty
easy to spot when washing down the cartridges.   Holes and tears can develop anywhere in the filter material.  

Missing Fittings – it
is not unusual for someone to put it back together wrong and leave out an essential fitting and create a void through which dirt and debris can return to the
pool.

Broken/Missing Air Relief Strainer – if the air
relief strainer is broken or missing, it will allow dirt back into the pool.