Filter Not Clearing Water
Fix filters that won't clear cloudy pool water
Poor Filtration Signs
👁️ Visual Symptoms
- • Persistent cloudiness
- • Slow clearing after shocking
- • Debris remains in water
- • Dull water appearance
🔍 Common Causes
- • Undersized filter
- • Worn filter media
- • Poor circulation
- • Chemistry imbalance
Quick Answer
When filters won't clear water despite running continuously, the problem is usually worn filter media, improper sizing, or water chemistry issues. First, test and balance water chemistry - high pH or low sanitizer prevents clearing. Check filter pressure and clean if needed. For sand filters over 5 years old, the sand may need replacement. Cartridge filters may be clogged with oils requiring degreaser cleaning. Ensure pump runs 8-12 hours daily and consider using clarifier to help filter capture fine particles.
Why Filters Fail to Clear Water
Media Problems
- • Old Sand: Becomes smooth, loses filtering ability
- • Clogged Cartridge: Oils and lotions embed in fabric
- • Channeling: Water finds paths through media
- • Calcified Media: Scale prevents proper filtration
- • Wrong Media Type: Incorrect sand grade or size
System Issues
- • Undersized Filter: Can't handle pool volume
- • Low Flow Rate: Pump too small or failing
- • Short Run Times: Insufficient daily filtration
- • Poor Circulation: Dead spots in pool
- • Bypassing: Water not going through media
Chemistry Impact:
Poor water chemistry makes particles too small to filter. High pH causes cloudiness that filters can't remove. Low sanitizer allows organics that pass through filters.
Filtration Troubleshooting
Step-by-Step Diagnosis
Test Water Chemistry
Check pH, alkalinity, and sanitizer levels. Poor chemistry prevents clearing.
Verify Run Time
Ensure filter runs 8-12 hours daily for proper turnover.
Check Filter Pressure
Compare current pressure to clean starting pressure.
⚠️ Warning: High pressure indicates dirty filter needing cleaning
Inspect Filter Media
Check condition of sand, cartridge, or DE grids.
Test Flow Rate
Verify pump provides adequate flow for filter size.
⚠️ Warning: Low flow reduces filter effectiveness
Check for Bypassing
Look for signs water is bypassing filter media.
Filter Type Performance
| Filter Type | Micron Rating | Clarity Level | Media Lifespan |
|---|---|---|---|
| Sand Filter | 20-40 microns | Good | 5-7 years |
| Cartridge Filter | 10-15 microns | Very Good | 1-2 years |
| DE Filter | 3-5 microns | Excellent | 5-7 years |
| Glass Media | 5-10 microns | Excellent | 10+ years |
Note: Smaller micron ratings capture finer particles. If your filter type can't achieve desired clarity, consider upgrading or using clarifiers to help.
Solutions by Filter Type
Sand Filter Solutions
Quick Fixes:
- • Deep backwash for 3-5 minutes
- • Add filter aid (DE or cellulose)
- • Use clarifier to clump particles
- • Check multiport valve position
Long-term Solutions:
- • Replace sand if over 5 years old
- • Upgrade to glass media
- • Add DE powder (1-2 cups) after backwash
- • Install larger filter if undersized
Cartridge Filter Solutions
Quick Fixes:
- • Deep clean with filter cleaner
- • Soak in degreaser overnight
- • Inspect for damage or wear
- • Rotate between two cartridges
Long-term Solutions:
- • Replace cartridge if over 2 years
- • Upgrade to larger cartridge
- • Install pre-filter skimmer basket
- • Add secondary filtration
DE Filter Solutions
Quick Fixes:
- • Backwash and recharge with fresh DE
- • Check for torn grids
- • Clean grids with filter cleaner
- • Verify proper DE amount
Long-term Solutions:
- • Replace damaged grids
- • Annual grid cleaning service
- • Check manifold for cracks
- • Upgrade to larger DE filter
Using Clarifiers Effectively
When Clarifiers Help
Clarifier Benefits:
- • Clumps tiny particles for easier filtration
- • Works with all filter types
- • Safe for swimming immediately
- • Helps remove dead algae
- • Improves filter efficiency
Application Tips:
- • Add weekly for maintenance
- • Double dose for cloudy water
- • Run filter continuously 24-48 hours
- • Clean filter after heavy use
- • Don't overdose - causes more cloudiness
Pro Tip: Clarifiers work best with proper water balance. Fix chemistry first, then add clarifier for fastest results.
Filtration Improvement Costs
Filter Service & Media Replacement
🔧 DIY Attempt
⚠️ Risks:
- • Choosing wrong filter media type
- • Improper media installation
- • Missing underlying problems
- • Damaging filter internals
- • Creating worse filtration issues
👷 Professional Service
✅ Includes:
- • Complete filtration system evaluation
- • Media inspection and replacement
- • System sizing verification
- • Flow rate testing
- • Water chemistry optimization
- • Filtration recommendations
💰 Value Tip: CoOpPools offers transparent pricing with no hidden fees. Our worker-owned model means fair prices and invested service.
Maintain Clear Water
Prevention Tips
Maintain Proper Chemistry
Balanced water is easier to filter and keeps clear
Regular Filter Cleaning
Clean filter based on pressure rise, not calendar
Replace Media On Schedule
Sand: 5-7 years, Cartridge: 1-2 years, DE grids: 5-7 years
Size Filter Correctly
Ensure filter matches pool volume and bather load
Run Pump Adequate Hours
Turn over pool water 1-2 times daily minimum
🏊 Pro Tip: Regular professional maintenance prevents 90% of pool problems.Get your maintenance quote today
Need Professional Help?
Can't get your pool water clear? Our filtration experts will diagnose why your filter isn't performing and provide solutions. We service all filter types, replace worn media, and optimize your system for crystal clear water. Stop fighting cloudy water - let us restore your filter's performance!
Mention "poor filtration" when calling for faster service
Related Pool Problems
Related Pool Problems
Cloudy Water
Often RelatedPrimary symptom of poor filtration
High Filter Pressure
Often RelatedDirty filter can't clear water
Short Filter Cycles
Sometimes RelatedFilter clogs quickly
💡 Did You Know? Pool problems often occur together.Filter Not Clearing Water can lead to or be caused by these related issues. Understanding the connections helps prevent future problems.