Which Type of Pool Filter Is the Best?
If you’re considering purchasing a swimming pool, you may be concerned about the maintenance you’ll have to undertake. Picking the pool that is right for you and your swimming needs is one thing. That will determine a good chunk of the required maintenance. But what about the type of filter you purchase? Surely filters need maintenance as well, which begs a few questions… which pool filter requires the lowest maintenance? Do they all filter the same amount of debris? Which type of pool filter is best?
The pool filter is the centerpiece of a pool’s equipment pad. The filter keeps your water clean by trapping dirt, debris, and contaminants inside the filter. The three most common types of pool filters are diatomaceous earth (D.E.) filters, sand filters, and cartridge filters. Although they all perform the same function, each one does it differently and thus requires different levels of maintenance.
In this article, we’ll break down the pros and cons of each filter type. At Royal Pools G2 Landscaping we have been building and maintaining inground pools for 25 years. In that time, we have had to maintain all three filter types. This article will help you decide which is best for your inground pool (vinyl liner, concrete, or fiberglass) or above-ground pool.
1. Diatomaceous Earth (D.E.) Filters
What is it?
Diatomaceous earth filters are comprised of a hard outer shell encasing multiple grids or “fingers” inside. D.E. is a powdery material made out of crushed seashells or the skeletal remains of microscopic sea organisms. The earth media coats the grids inside the filter which then catches debris as it enters the filter from the pump.
D.E. is the strongest swimming pool filter media on the market. These filters can capture debris up to 5 microns and in some cases up to 2 microns small.
(Microns are a unit of measurement. One micron is about one-millionth of a meter or 1/25,000 of an inch)
Pros:
- Superior filtration: Captures the smallest particles (down to 2 microns)
- Crystal-clear water: The best option for high-visibility, pristine water
- Efficient: Requires shorter filtration times
Cons:
- More expensive: Higher upfront cost and recurring costs for D.E. powder
- More maintenance: Filter should be backwashed regularly and grids must be cleaned thoroughly every month or two depending on swimmer load; D.E. powder clogs easily and must be recharged after every cleaning and backwash.
- Replacing D.E. Grids/Fingers: whether your D.E. filter has grids or fingers, they will need to be replaced every five years or so depending on the level of degradation.
- Higher water usage: Backwashing uses a significant amount of water, which will have to be replenished if the pool water level gets too low.
Maintenance:
- Requires backwashing when pressure rises 8-10 marks above the ideal range (typically somewhere between 5-25).
- Must add new D.E. powder after each backwash
- Monthly deep cleaning of the filter grids (minimum every other month)
Best for:
- Pools where water clarity is a top priority
- High-use residential pools or those in dusty or leafy environments
2. Cartridge Filters
What is it?
Cartridge filters are the second strongest pool filter type. In these filters, a shell encases one or several cartridges in cartridge filters. The cartridges themselves are tubular pieces of polyester, paper, polypropylene, and activated carbon.
When debris flows through a cartridge filter, the pleated grooves of the cartridges trap debris from going back into the pool. A cartridge filter can trap debris 10-20 microns in size.
Pros:
- Efficient filtration: Finer than sand, less than D.E.
- No backwashing: Saves water and lowers energy bills
- Easy maintenance: Remove and rinse cartridges with a garden hose
Cons:
- More frequent cleaning: Cartridges need to be cleaned every few weeks
- Higher cost for replacement: Cartridges typically last 1–3 years
- May clog easily in pools with heavy debris
Maintenance:
- Hose off cartridges every 2–4 weeks depending on debris levels
- Deep clean with filter cleaner as needed
- Replace cartridges every 1–3 years
How To Maintain A Cartridge Filter
Best for:
- Eco-conscious owners wanting to reduce water waste
- Pool owners looking for better filtration than sand but without the complexity of D.E.
3. Sand Filters
What is it?
A sand filter traps debris in a very simple way. These filters are usually a large round shell encasing large amounts of sand. Water is sucked into the filter at the top of the shell and trickles through the sand to the bottom, trapping debris in the filter.
The clean water is then sucked back up into the laterals at the bottom of the filter shell, sending debris-free water back into the pool.
In terms of filtration power, sand is the weakest, capturing particles 20–40 microns in size. They are, however, the most widely used type of pool filter due to their simplicity, ease of maintenance, and affordability.
Pros:
- Low maintenance: Requires backwashing every few weeks. Does not need to be taken apart and deep cleaned the way cartridge and D.E. filters do.
- Affordable: Lower upfront and maintenance costs
Cons:
- Weaker filtration: Less effective at capturing very fine debris when compared to cartridge and D.E. filters
- Higher water usage: Backwashing uses a significant amount of water, which will have to be replenished if the pool water level gets too low.
- Cost to replace sand: Pool filter sand needs to be changed every 5-7 years, which will add to the overall lifetime cost.
Maintenance:
- Backwash every 3–4 weeks (or when the pressure gauge rises 8–10 PSI)
- Replace sand every 5–7 years
Best for:
- Budget-conscious homeowners who want minimal maintenance
- Pools with minimal debris or moderate use
Conclusion: Which Pool Filter is Best?
| Pool Type | Best Filter Option | Reason |
| Inground Concrete Pool | Diatomaceous Earth (D.E.) | Best filtration and clarity for demanding environments |
| Inground Fiberglass Pool | Cartridge or Sand | Great balance of clarity and water efficiency |
| Inground Vinyl Liner Pool | Cartridge or Sand | Budget-friendly (sand) or low-maintenance (cartridge) options |
| Above-Ground Pool | Cartridge or Sand | Easy upkeep (sand) or improved clarity (cartridge) |
Final Thoughts
The best pool filter depends on your swimming pool type, usage, budget, and your willingness to handle pool maintenance. If water clarity is your top priority, go with a diatomaceous earth filter. For a balance of efficiency and low upkeep, a cartridge filter might be your best bet. And if you want something simple and affordable, a sand filter gets the job done with minimal fuss.
For more educational content on all things pools and landscaping, check out our learning hub at the top of our page. Happy hunting!
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Written by Logan Edgemon