Fed up with cartridge filters...

[waterbear]

Once you convert you will need to replace the filter again most likely

[b2001]

From personal experience over 3 years, I will agree with all of the comments above that bacquacil is the root cause of the problem. I was also going to convert to a sand filter, or run sand and cartiridge filters in parallel (only one on at a time). I got tired of the ritual on constantly cleaning the cartridge filter, and I never had much success with the filter cleaner or muriatic acid cleanup, just an environmental mess afterwards.

The best trick I found to get improved filter performance was to wash the filter down and let it dry out - I usually had several filters on tap - for a week or so.

I've had no problems with the cartridge filter since converting to chlorine and abandoned the idea of a sand filter - and I've only had one cartridge filter for this season. The filter pressure never strays from 10 psi - I do wash it down once a week ...