Pool Filter Repair, Replacement & Upgrades
Cloudy water or poor circulation? Schedule a filter evaluation — we carry common replacement media and DE grids for same-visit service.
The Three Types of Pool Filters
Each filter type has different maintenance requirements, filtration precision, and cost profiles. We install and service all three.
Sand Filter
Filters particles ≥ 20–40 microns
Advantages
- ✓Low cost to purchase and maintain
- ✓Backwash to clean — no media replacement for 3–5 years
- ✓Simple operation; beginner-friendly
Considerations
- –Least precise filtration
- –Backwashing wastes water (50–100 gal per cycle)
- –Sand channel over time, reducing effectiveness
Typical installed cost
$400 – $800 installed
Maintenance cycle
Backwash every 1–4 weeks; sand media replacement every 3–5 years
Cartridge Filter
Filters particles ≥ 10–15 microns
Advantages
- ✓Better filtration than sand; no backwash needed
- ✓Lower water waste
- ✓Energy-efficient (lower head pressure = less pump work)
Considerations
- –Cartridges need regular rinsing and annual replacement
- –Less effective with very heavy debris loads
Typical installed cost
$500 – $1,000 installed
Maintenance cycle
Rinse every 2–4 weeks; replace annually or as needed
Diatomaceous Earth (DE) Filter
Filters particles ≥ 2–5 microns
Advantages
- ✓Finest filtration of all three types
- ✓Produces the clearest water achievable by mechanical filtration
- ✓Ideal for pools with heavy use or sensitive swimmers
Considerations
- –More complex maintenance
- –Requires regular DE powder recharge after backwashing
- –DE disposal requires care per local environmental rules
Typical installed cost
$700 – $1,400 installed
Maintenance cycle
Backwash and recharge DE powder every 2–4 weeks; annual breakdown clean
Skimmer Inspection Included in Every Visit
Pool skimmers pull floating debris, oils, and sunscreen from the water surface before they can sink and decompose. A malfunctioning or cracked skimmer isn’t just a maintenance nuisance — it’s a common source of pool leaks and reduced circulation efficiency.
We inspect skimmers as part of every service visit and can replace failing units with direct-fit modern equivalents that restore proper surface skimming without modifying your existing plumbing.
- ✓Cracked skimmer body (top leak source in gunite pools)
- ✓Failed skimmer throat and weir door replacement
- ✓Skimmer basket and lid replacement
- ✓Full skimmer replacement including concrete repair
- ✓Equalizer line inspection and repair
- ✓Skimmer plumbing line pressure testing
When to Upgrade Your Filter
Filter is 10+ years old
Aging filters lose their structural integrity and filtration precision — replacing a decade-old filter often immediately improves water clarity.
Chronic cloudy water
If your water stays cloudy despite correct chemical balance, the filter may be undersized for your pool volume or simply worn out.
High filter pressure despite cleaning
A filter that won't drop pressure after cleaning often has channeled sand, worn DE grids, or damaged cartridge elements.
Visible cracks or leaks on tank
A cracked filter tank is a safety hazard — these operate at pressure and must be replaced immediately if the tank body fails.
Is My Filter Big Enough?
Filter sizing is based on pool volume (gallons) and desired turnover rate. An undersized filter strains your pump, increases chemical use, and can't maintain water clarity regardless of how often it's cleaned. Here are general sizing benchmarks:
Up to 20,000 gallons
Cartridge: 150–200 sq ft
DE: 36–48 sq ft
Sand: 19–21" tank
20,000 – 35,000 gallons
Cartridge: 250–320 sq ft
DE: 48–60 sq ft
Sand: 23–24" tank
35,000+ gallons
Cartridge: 400+ sq ft
DE: 72+ sq ft
Sand: 26–30" tank
These are minimum recommendations. Larger is always better for filtration clarity. Our technicians calculate the correct size based on your pool's volume and pump flow rate during a service visit.
Total Equipment Coverage
Upgrade filters alongside your pump
Filtration upgrades perform best when matched to pump flow rates. If you’re upgrading to a variable-speed pump, it’s the right time to evaluate your filter size and type. View all equipment services.
Related Services
Skimmer Repair & Replacement →
Skimmers and filters work together — a cracked skimmer undermines even a properly sized filter system.
Pool Pump Repair →
Pump flow rate must match your filter's capacity — we evaluate both during every equipment service.
Pool Leak Detection →
Cloudy water despite a healthy filter and balanced chemistry can indicate active water loss — we'll find it.
What Our Customers Say
February 2025
“I had been searching for a new company for my weekly pool maintenance when I came across Beltway Pools, and I'm so glad I did. Sandra has been managing our pool's opening and weekly maintenance, and her attention to detail and expertise are truly outstanding. She has been incredibly patient with all my questions and maintains a friendly and professional demeanor at all times. Thanks to Sandra and her maintenance team, our pool is exceptionally clean and well-maintained. I cannot recommend Beltway Pools enough!”
May 2025
“Beltway Pools saved us when our pool was leaking. The team was quick to diagnose the issue, and Dragan made sure everything was fixed properly. The repair process was smooth and efficient.”
January 2026
“Rob was fantastic at always keeping up communication and walking us through each step of the process for our pool renovation. The pool turned out fantastic and his team made sure all of my questions/concerns were addressed. Couldn’t be happier! Services Swimming pool crack repair, Swimming pool resurfacing, Swimming pool tile repair, Swimming pool equipment repair”
Areas We Serve
Serving homeowners across Northern Virginia, Maryland & Washington, DC.
View all service areasPool Filtration — Frequently Asked Questions
How often should I replace my pool filter?
Filter replacement intervals vary by type:
- Cartridge filters — cartridges typically last 1–3 years with regular cleaning; the tank and housing can last 10–15+ years
- Sand filters — sand media should be replaced every 5–7 years; the tank typically lasts 15–20+ years with proper maintenance
- DE (diatomaceous earth) filters — grids/fingers need periodic replacement every 3–6 years depending on condition; DE powder must be recharged after each backwash
Any filter showing cracked tanks, broken laterals, or consistently poor filtration performance should be evaluated for replacement regardless of age.
What is the difference between sand, cartridge, and DE pool filters?
All three types remove particles from pool water but differ in filtration fineness, maintenance, and cost:
- Sand filter — filters particles down to ~20–40 microns; lowest maintenance (backwash to clean); lowest upfront cost. Common on older pools.
- Cartridge filter — filters down to ~10–15 microns; cleaning involves removing and hosing down cartridge elements; no backwashing; moderate cost. Most popular for new residential pools.
- DE (diatomaceous earth) filter — finest filtration at ~3–5 microns; requires backwashing and recharging with DE powder; highest maintenance but best water clarity. Often used on pools where crystal-clear water is a priority.
We can advise which type is optimal for your pool size, bather load, and maintenance preference during a service visit.
How much does it cost to replace a pool filter in the DMV?
Pool filter replacement costs in Northern Virginia and Maryland:
- Cartridge filter replacement — $800–$1,800 installed (filter tank + first cartridge set)
- Sand filter replacement — $700–$1,500 installed
- DE filter replacement — $1,200–$2,500 installed
- Cartridge element replacement only (existing tank) — $150–$400
- Sand media replacement only (existing tank) — $200–$400
Pricing varies by filter size (measured in square footage or flow rate) and plumbing compatibility. Request a quote for your specific system.
How do I know if my pool filter needs replacing?
Signs your pool filter needs service or replacement:
- Cloudy water that won't clear despite correct chemical levels — the filter isn't polishing the water effectively
- High pressure gauge readings that don't normalize after cleaning or backwashing — indicates internal restriction or damaged media
- Short filter cycles — filter gets dirty unusually quickly (can indicate algae, broken grid, or undersized filter)
- Visible cracks or damage on the tank body, collar, or valve
- DE powder returning to the pool — indicates broken grids or fingers inside the filter
If you're seeing any of these, schedule a diagnostic visit — it may be a simple service or a replacement recommendation.