Sand vs. DE vs. Cartridge Filters: What’s the Difference?

Your pool filter is one of the most important tools for cleaning and maintaining water. Your pool filter circulates the water in the pool and catches unwanted debris and particles. There are a couple of options to choose from when deciding which type of filter to invest in. These options are sand filters, DE (diatomaceous earth) filters, and cartridge filters. Each of these options has different benefits and uses.

In this article, I have outlined information about each filter type and its pros and cons. For specific filter recommendations, head to my guide on the best pool filters.

Main Takeaways

• Sand filters use rough sand to filter out the debris in the pool. It is the cheapest pool filter option and is super low maintenance, but it is not as effective as other filter options.
• DE filters use powder-like substances made of fossils to filter out the debris. This is the most effective filter option as it can filter debris as small as 5 microns, but it is the most expensive pool filter to set up and maintain.
• Cartridge filters use polyester screens to filter the pool water. It doesn’t require any backwashing and is reasonably cheap, but the cartridges need to be changed every 2 to 3 years, which can add up in costs.

Sand Filter

Diagram: A) Pressure gauge, B) Air relief valve, C) Air relief tube, D) Diffuser, E) Lateral assembly

Sand filters use rough sand, generally made of silica or fiberglass, to filter out debris in the pool water. The sand used in pool filters is specifically designed to be sharper and more rigid, which helps to catch more particles. Water is pumped from the pool into the filter, and over time the sand will collect lots of debris, algae, and other contaminants.

The sand only needs to be replaced every 5 to 7 years (you can read my guide on how to change your pool filter sand), but you will need to clean out the filter every 1 to 4 weeks. Sand filters are the most common filter used in residential swimming pools. This is due to their easy maintenance and inexpensive setup.

Pros of Using a Sand Filter

• Inexpensive to initially purchase and set up (around $300 to $1,200). Sand filters are probably the cheapest pool filter option.
• The sand does not need to be replaced often. You can keep the same sand for 5 to 7 years.
• Very low maintenance and super easy to clean. A sand filter requires very little upkeep. You will need to clean it every week or so, but the backwashing process is simple to carry out.

Cons of Using a Sand Filter

• You will have to clean and backwash the filter every 1 to 4 weeks which uses a lot of water and can be expensive and wasteful. If you are looking for an option that requires less manual cleaning, look at cartridge filters.
• Sand filters can only filter particles that are 20 to 40 microns. Diatomaceous earth and cartridge filters can filter much smaller particles. Because of this, sand filters are considered the least efficient filtration option.
• The filter builds up pressure over time which decreases its effectiveness.

DE Filter

Diagram: A) Upper manifold, B) Standpipe, C) Bulkheads, D) Pressure gauge, E) Air relief valve, F) Air relief tube, G) Grids

A DE filter is a powder-like substance that is much smaller than sand. DE, or diatomaceous earth, is made up of tiny fossils crushed into a fine powder. These particles can be poured directly into your skimmer, and then they will collect on the filter grid. DE (diatomaceous earth) is such a fine substance that it can stop even tiny substances from reentering the pool.

While sand will filter out 20 to 40 micron particles, DE can filter out 5 to 10 micron-sized particles. This means much cleaner water and less debris floating around. However, DE filters are pretty expensive, and they require a backwash and cleaning every 1 to 2 months.

Pros of Using a DE Filter

• This is the most efficient filter option as it can filter out particles as small as 5 microns. For reference, that is smaller than a red blood cell!
• It is very easy to add more DE powder because it can be added directly through the pool skimmer.
• Great for larger pools and commercial pools, but it can be used in any sized pool.
• You do not need to use heavy-duty chemicals when cleaning out the filter.

Cons of Using a DE Filter

• This is the most expensive pool filter option to initially set up, and it is also the most costly to maintain.
• You must clean and replace the DE every 1 to 2 months, which can be tiring work.
• The fine powder can harm your lungs if inhaled. So always make sure to wear a safety respirator when replacing the DE.
• The filter grids require replacing every 2 to 3 years because they will deteriorate.

Cartridge Filters

Diagram: A) Pressure gauge, B) Dirt and debris gets trapped here as water passes through, C) Bulkheads, D) Air relief valve, E) Air relief tube, F) Cartridges, G) Lower manifold

Cartridge filters are an excellent option for better filtration than sand but are more affordable than DE. Cartridge filters use synthetic polyester screens as a filter medium. Pool water is pumped through, and particles get stuck to the filter medium. They do not require backwashing to be cleaned. You will need to remove the cartridge and spray off the algae and debris with a garden hose. I also have complete guides on how to clean a pool filter cartridge and replacing your cartridge filter if you’re interested.

Pros of Using a Cartridge Filter

• A great low-cost option for small to medium-sized pools. Many pool owners use these for hot tubs and spas.
• Cartridge filters will clear out smaller particles than sand filters at about 10 to 15 microns.
• Does not have much of an effect on the chemical levels.
• This is the only filter option that does not require backwashing, so you will save money on water.
• It is a reasonably cheap option considering the efficiency.

Cons of Using a Cartridge Filter

• Cartridges need to be changed every 2 to 3 years which can be expensive.
• The filter needs to be taken apart and deep cleaned a couple of times a year. This involves spraying it with water and possibly using muriatic acid to kill microbes living in the filter.
• Cartridges are also not reasonable for larger commercial pools.
• Fairly high initial cost set up.
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Sand vs. DE vs. Cartridge Filter Comparison Chart

Ultimately, How Do You Choose?

With so many pros and cons, it can be overwhelming to decide the type of pool filter that works best for you. In the end, it comes down to taking a look at your pool and considering a few factors.

• The amount of money you are willing to invest
• The size and deepness of your pool
• How much time you can spend cleaning and maintaining the filter.

On that last point, I wrote some individual articles for each pool filter type on troubleshooting and maintenance, which you can read here:

• Sand filter maintenance
• DE filter maintenance
• Cartridge filter maintenance

Weigh these details and talk to a pool expert if necessary. It is an important decision that can save you time and money. At the end of the day, all 3 options can keep your pool clear and sparkling throughout the summer season.

Let me know if you have any further questions, as I am happy to help!