What is the best filter for an inground pool?

I work for a pool company and have found that a sand filter is the most common. An earth filter provides the best filtration but can be more time consuming and can cause a problem when using a bacquacil pool. (ie, frequent clogging). There is also cartridge filters but i find those to be less efficient compared to the sand and earth. hope this helped!

I would suggest that each type of filter has its own advantages and disadvantages;

Sand: Affordable, dependable, easy to maintain, but not the highest level of filtration and cleaning (backflushing) wastes water and can be a mess. Most common for both above and in-ground pools.

Cartridge: Better filtration than sand, very easy to maintain and clean, but more expensive. Good for above ground pools.

DE: Great filtration, but more expensive and more difficult to clean than sand or cartridge. Great for in-ground pools.

...