Pool filter cleaning depends on your filter type. Cartridge filters need rinsing and rotation every 2-4 weeks, sand filters require backwashing when pressure rises 8-10 PSI, and DE filters need backwashing and fresh DE powder.
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First, let's diagnose what type of cleaning your pool filter needs. The cleaning method varies dramatically depending on whether you have a cartridge, sand, or diatomaceous earth (DE) filter, and the current condition of your system.
Check your pressure gauge first. If pressure has risen 8-10 PSI above your clean starting pressure (typically 12-15 PSI when clean), your filter needs attention. Also look for reduced water flow from return jets, cloudy water that won't clear despite proper chemistry, or if it's been 2-4 weeks since your last cleaning.
For cartridge filters, you'll need a rotation system with multiple sets of cartridges. Remove the dirty cartridges and rinse them with a garden hose using a spray nozzle, working from top to bottom. Spray between each pleat to remove debris.
Soak heavily soiled cartridges overnight in a cartridge cleaner solution or 1 cup TSP per 5 gallons of water. Never use a pressure washer or brush aggressively as this damages the filter media.
Sand filters require backwashing when pressure rises significantly. The process reverses water flow to flush trapped debris from the sand bed.
Warning: Never move the multiport valve while the pump is running as this can damage the valve assembly and create costly repairs.
Sand should be replaced every 3-5 years as it becomes rounded and less effective. If backwashing doesn't reduce pressure significantly, you may need fresh sand.
DE filters provide the finest filtration but require more maintenance. They need backwashing plus fresh DE powder after each cleaning.
Monthly, you should disassemble DE filters to clean the grids directly. Remove grids and spray clean, checking for tears or damage. Soak in TSP solution if heavily coated with oils or debris.
Maintain proper water chemistry to reduce filter workload. Keep FC (free chlorine) at appropriate levels based on your CYA (stabilizer) level - typically 7.5% of CYA reading. For example, with 40 ppm CYA, maintain 3 ppm FC minimum.
pH should stay between 7.4-7.6 for optimal filtration and sanitizer effectiveness. High pH reduces chlorine efficiency, leading to more organics that clog filters faster.
If filters clog quickly after cleaning, investigate root causes. Test your water chemistry - high bather loads, algae blooms, or environmental contamination create extra debris.
Short filter cycles often indicate inadequate circulation time. Run your pump 8-12 hours daily minimum, with circulation during peak sunlight hours when algae growth is highest.
Cloudy water persisting after filter cleaning may require a SLAM (Shock Level And Maintain) process. Raise FC to shock level based on CYA and maintain until water clears and chlorine loss stops overnight.
Establish a regular cleaning schedule rather than waiting for high pressure. Cartridge filters benefit from 2-week rotations, while sand and DE filters should be backwashed when pressure rises 8 PSI.
Keep detailed records of cleaning dates and pressure readings. This helps identify patterns and optimize your maintenance schedule based on actual usage and environmental conditions.
Consider upgrading to variable speed pumps which can extend filter cycles through improved circulation patterns and energy efficiency.
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