There are two answers to this question, subjective and objective. Objectively, we only have to look at the filtering capabilities to each and we can come to the conclusion that pool cartridge filters do a superior job at filtering your pool water as it filters out particles down to 10 microns in size as compared to pool sand filters that filter out particles only down to 20 microns in size.
At this point, people will assume that there are more pool cartridge filter users than pool sand filter users, but that’s not the case. There are actually a lot more pool sand filter users out there than cartridge filter users, the reason? There are a number of reasons why many people still prefer pool sand filters over cartridge filter.
Before we dive deeper, here's a quick recap from Mr Pool Man himself on the basic differences between sand pool filters and cartridge filters