Expert Verified Updated: March 2026

Cartridge Filter Size Calculator

Determine the optimal square footage for your cartridge filter based on pool volume and turnover requirements.

Quick Conclusion
For a standard residential pool, aim for 1 sq. ft. of filter area per 1,000 gallons of water. For example, a 20,000-gallon pool requires a minimum 200 sq. ft. cartridge filter. Oversizing reduces cleaning frequency and extends cartridge life.

Technical Comparison

Pool Volume Min Filter Area Cleaning Interval
10,000 Gallons 100 sq ft ~4 Months
20,000 Gallons 200 sq ft ~6 Months
30,000 Gallons 300+ sq ft ~8-12 Months

Actionable Steps

Pro-Tip

The "Sunlight" Warning: Cartridge filters use pleated polyester media that is sensitive to UV light. If you leave your cartridges out in the sun to dry after cleaning, the fibers will become brittle and lose their filtration efficiency. Always dry your cartridges in a shaded, well-ventilated area.

Frequently Asked Questions

Can I upgrade?

Yes, you can almost always replace a small filter with a larger one if it fits your pad.

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