Many filter manufacturers for residential pools go by a filtering capacity at maximum flow rate for one turnover in 6 hours. For my filter, the max. flow rate is 127 GPM so that works out to 127*60*6 = 45,720 gallons as their maximum pool size to support, but that's not particularly realistic. The filter area for a cartridge filter just means how long you can go between filter cleanings. With more filter area, you can go longer. I'm able to clean mine just once a year, but I have a pool cover that keeps the pool pretty clean most of the time. If I didn't have the cover, I'd probably have to clean more often. My filter is probably oversized about double, but again there's no exact magic number here. Clearly, yours is even more oversized. That is not a bad thing -- you probably don't have to clean your filter very often.

The other extreme is getting a small cartridge filter with one cartridge that you would need to clean more frequently, possibly monthly. Some people find that easier to do. There is no question that cleaning my 4-cartridge system is a PITA, but only having to do it once a year isn't so bad.