Your filter system is one of the most important parts of your pool. Getting the perfect one for your pool is key to a clean, safe, and fun backyard oasis. Choose from a sand filter, a cartridge filter, or a Diatomaceous Earth (DE) filter. Make sure you get the right size for your pool and look into proper maintenance for the filter, whatever type you decide.
Check out the Filter Buyer’s Guide and FAQ page for more information and answers to any questions.
Depending on how well they’re maintained, the size of your pool, water chemistry, and what type of filter you have, filters can last between three and seven years. Cartridge filters can last two to four years with proper maintenance and cleaning. The casing on a sand filter can last for over ten years, but the sand inside should be replaced every three to seven years. DE (or Diatomaceous Earth) filters typically last four to six years.
Pool filters should be cleaned regularly. A good rule of thumb is to clean them whenever the pressure gauge shows an increase of 8 - 10 PSI above the normal operating pressure. Typically, this can be every six months. The frequency depends on how much you use your pool, the amount of debris being filtered out, and the type of filter you have.
The first step is to calculate how many gallons your pool is. Our blog has a great guide - How to Calculate Gallons in a Pool (Without Overthinking It). But for a quick reference of the most common pool sizes, refer to the tables below:
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POOL SIZE
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48" WALL HEIGHT
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52" WALL HEIGHT
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12' Round
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3,000 Gallons
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3,400 Gallons
|
|
15' Round
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5,000 Gallons
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5,300 Gallons
|
|
18' Round
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7,000 Gallons
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7,500 Gallons
|
|
20' Round
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8,000 Gallons
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9,500 Gallons
|
|
21' Round
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9,000 Gallons
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10,500 Gallons
|
|
24' Round
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12,000 Gallons
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13,500 Gallons
|
|
28' Round
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16,000 Gallons
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18,500 Gallons
|
|
30' Round
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18,500 Gallons
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21,000 Gallons
|
|
POOL SIZE
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48" WALL HEIGHT
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52" WALL HEIGHT
|
|
11' x 18' Oval
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4,700 Gallons
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5,300 Gallons
|
|
12' x 24' Oval
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6,800 Gallons
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8,000 Gallons
|
|
15' x 25' Oval
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9,000 Gallons
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10,000 Gallons
|
|
15' x 27' Oval
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10,000 Gallons
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11,000 Gallons
|
|
15' x 30' Oval
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12,000 Gallons
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14,000 Gallons
|
|
16' x 32' Oval
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12,000 Gallons
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14,000 Gallons
|
|
18' x 33' Oval
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14,000 Gallons
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16,000 Gallons
|
|
21' x 38' Oval
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19,000 Gallons
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21,000 Gallons
|
|
21' x 41' Oval
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20,000 Gallons
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23,000 Gallons
|
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OPTIMAL FILTER FOR POOL SIZES
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POOL GALLONS
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PUMP SIZE
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INTAKE LINES (MINIMUM)
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RECOMMENDED FILTER SIZE
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10,000
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0.75 HP
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1-1.5"
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SAND: 3.0 Sq Ft
CARTRIDGE: 100-200 Sq Ft DE: 36 Sq Ft |
|
15,000
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1.0 HP
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1-2.0"
|
|
|
20,000
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1.5 HP
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2-1.5" or 1-2.0"
|
SAND: 3.9 Sq Ft
CARTRIDGE: 300-400 Sq Ft DE: 48 Sq Ft |
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25,000
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1.5 HP
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2-1.5" 1-2.0"
|
|
|
30,000
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2.0 HP
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4-1.5" or 2-2.0"
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SAND: 4.9 Sq Ft
CARTRIDGE: 400-500 Sq Ft DE: 60 Sq Ft |
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35,000
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2.0 HP
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2-1.5" or 1-2.0"
|
|
|
40,000
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2.5 HP
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3-2.0"
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SAND: 6.9 Sq Ft
CARTRIDGE: 500+ Sq Ft DE: 72 Sq Ft |
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45,500
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2.5 HP
|
3-2.0"
|
|
If you can’t remember your pump's HP and flow rate, you should be able to find this information on the pump. If not, base your filter choice on the size of your pool.
Opting for a filter smaller than your pool's recommended size would result in prolonged cleaning and sanitization processes. Not only would a smaller filter consume a significant amount of time to clean your pool, but it would also put excessive strain on your pump. Since the pump and filter work together, a lack of synchronization can harm your entire system.
A conventional sand filter can only filter particles as small as 20 microns, but this capability can be improved by utilizing appropriate equipment. Various additives and replacement parts are available that can enhance the performance of sand filters. These options include Luster Filter Media, Zeo-Clear Swimming Pool Sand Filter Alternative, and Filter Glass.
