Thanks to all for your suggestions. So my pump just stopped working yesterday (that's something beyond my capabilities) so I called my local pool guy. Luckily, it's a type that he can just remove the motor and replace it instead of having to put a whole new pump on. Anyway, I mentioned the filter situation to him, and he doesn't recommend trying to replace the 'innards" with another cartridge system, like the Pentair clean and clear. Just his opinion I guess.