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 super low maintenance, but it is not as effective as other 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 or use sand filter balls.
- 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.
Best Sand Filters
If you’re looking at purchasing a sand filter for your pool, these are the brands and models I recommend:
- Hayward ProSeries Sand Filter
- XtremepowerUS Inground Pool Sand Filter
- Pentair Sand Dollar SD60 Sand Filter Tank
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. You can pour these particles 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- 40 micron particles, DE can filter out 5- 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.
Best DE Filters
Here are my top recommendations for DE filters:
- Hayward ProGrid D.E. Pool Filter
- Hayward Perflex DE Pool Filter
- Pentair Quad Cartridge Style DE Pool Filter
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. Instead, 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 in learning more.
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.
Best Cartridge Filters
Looking to upgrade to a cartridge filter? I’ve got you covered with my top cartridge filter picks:
- Hayward SwimClear Plus Cartridge Pool Filter
- Blue Wave 120-Square Feet Cartridge Filter System with 1.5 HP Pump
- Pentair Clean and Clear Plus Cartridge Filter
What Is a Micron?
Okay, so we’ve had a lot of talk about microns. You might have a vague idea of what it is, but exactly what is it, and how small is a micron? Generally, when it comes to filters, the smaller the micron it can filter, the better. A typical pool filter will generally filter down to 5 to 40 microns.
Microns, also called micrometers, are a unit of measurement. They measure one-millionth of a meter or 1/26,000 of an inch. That tiny measurement can be pretty difficult to grasp, so let’s put it into perspective. The naked human eye can only see particles measuring around 50 to 60 microns.
Here are some common things measured in microns so you can see exactly how small this measurement is:
- Length of a typical bacterium: 1 to 10 microns
- Thickness of spider silk: 3 to 8 microns
- Droplet of fog, mist, or cloud: 10 microns
- Diameter of human red blood cell: 10 microns
Sand vs. DE vs. Cartridge Filter Comparison Chart
| Sand filter | DE filter | Cartridge filter | |
| Filter media | Sand, fiberglass, or silica | Diatomaceous earth | Synthetic polyester screens |
| Filter efficiency | 20-40 microns, lowest efficiency | 5-10 microns, highest efficiency | 10-15 microns, medium efficiency |
| Filter media lifespan | Sand needs replacing every 5-7 years | DE needs to be replaced after every backwash, so every 1-2 months | The cartridge needs to be replaced every 2-3 years |
| Initial cost | $250 to $1,000 plus labor cost if needed | $550 to $1,800 plus labor cost if needed | $250 to $1600 plus labor if needed |
| Ongoing cost | New bag of filter sand costs $25-$100 | New bag of diatomaceous earth costs $170 for a 50 lbs bag. | N/A |
| Replacement cost | N/A | New filter grids cost about $100 | New filter cartridges cost about $200 for a 4 pack |
| Water usage | Up to 7,000L per year if you backwash every week for the entire season | Up to 4,000L per year | Does not require backwashing, so there is minimal water usage |
| Durability | Will generally last 15-25 years if maintained well. | Filter grids will last around 7-10 years. The entire piece of equipment will last 10-20 years | Can last up to 25 years. |
| Time spent cleaning | Requires about 30 min-1 hour of cleaning every 1-4 weeks. | About 45min-1hour every 1-2 months | Requires about 1 hour of cleaning 2-3 times per year |
FAQ
What Is the Most Effective Type of Pool Filter?
DE filters have the strongest filtration ability, able to filter down to 5 microns, and are considered the most effective type of pool filter.
What Is the Easiest Type of Pool Filter to Maintain?
Cartridge filters are the easiest type of pool filter to maintain. Instead of backwashing your filter often, you simply need to remove the cartridges and give them a rinse every few months.
What Is the Most Common Type of Pool Filter?
The most common type of pool filter is a sand filter. Sand filters are cheap and easy to come across. Cartridge filters are also climbing in popularity, but only in private residential pools.
Ultimately, How Do You Choose?
With so many pros and cons, deciding the type of pool filter that works best for you can be overwhelming. Ultimately, it comes down to looking 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:
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!
