🌊 Certikin FDB500 Deep Bed Sand Filter with Multiport Valve – 500mm Diameter, 9.5m³/h Flow Rate

Superior deep bed filtration for crystal clear pool water all season long

💧 Product Overview

The Certikin FDB500 Deep Bed Sand Filter represents the pinnacle of residential pool filtration technology, engineered for pool owners who demand exceptional water clarity and reduced maintenance. This premium 500mm diameter sand filter features an extended media bed depth that provides significantly longer contact time between pool water and filter media, resulting in superior particle capture and enhanced dirt retention capacity.

Manufactured using advanced bobbin-wound fibreglass and polyester resin construction, the FDB500 delivers professional-grade durability backed by Certikin’s renowned quality standards. The side-mounted 6-way multiport valve comes pre-installed, offering intuitive operation for all filtration, backwashing, and maintenance functions. Whether you’re maintaining a medium-sized residential pool or upgrading from a standard depth filter, the FDB500 delivers the performance and reliability that UK pool owners have trusted for decades.

Ideal for pools up to approximately 57,000-76,000 litres, this filter pairs the convenience of a compact 500mm footprint with the enhanced filtration capabilities that only a true deep bed design can provide.

✨ Key Features

✅ Deep Bed Filtration Technology – Extended media bed depth provides longer water contact time for superior particle removal and increased dirt holding capacity compared to standard filters

✅ High-Performance Flow Rate – 9.5m³/h maximum flow rate handles pools up to 76,000 litres with optimal 8-hour turnover times

✅ Premium Fibreglass Construction – Bobbin-wound polyester resin and fibreglass tank ensures exceptional strength, corrosion resistance, and long service life

✅ Side-Mount Multiport Valve Included – Factory-fitted 6-way multiport valve with 1½” connections for straightforward installation and intuitive operation

✅ Integrated Pressure Gauge – Built-in pressure monitoring enables precise backwash timing for optimal filtration efficiency

✅ Manual Air Vent – Allows easy release of trapped air to maintain consistent filtration performance

✅ Manual Water Drain – Simplifies winterisation and maintenance procedures for UK climate conditions

✅ Large Media Capacity – 195kg sand capacity maximises filtration surface area and extends backwash intervals

✅ Maximum 2.5 Bar Working Pressure – Robust pressure rating ensures safe operation across varied pump configurations

✅ Compatible with Multiple Media Types – Accepts sand, glass media, or zeolite for customised filtration performance

🔧 Technical Specifications

Specification	Value
Filter Type	Deep Bed Sand Filter
Model	FDB500
Tank Diameter	500mm
Connections	1½” (38mm)
Flow Rate	9.5m³/h (9,500 L/h)
Filtration Area	0.19m²
Filtration Rating	20-40 microns (with sand media)
Media Capacity	195kg
Maximum Working Pressure	2.5 bar
Tank Material	Fibreglass reinforced polyester resin
Valve Type	6-way side-mount multiport
Valve Included	Yes
Pressure Gauge	Included
Air Vent	Manual
Water Drain	Manual
Manufacturer	Certikin (Fluidra Group)

📏 Pool Sizing Guide

The Certikin FDB500 is designed to maintain optimal water clarity when correctly matched to your pool volume. Pool filtration systems should turn over the entire pool volume within 6-8 hours for residential installations.

Sizing Calculation:

Required Flow Rate (m³/h) = Pool Volume (m³) ÷ Turnover Time (hours)

Pool Size Compatibility:

Pool Type	Volume Range	Suitability
🏊 Medium Above-Ground	20,000-40,000 L	✅ Excellent – optimal performance
🏊 Large Above-Ground	40,000-60,000 L	✅ Very Good – ideal match
🏠 Small In-Ground	Up to 50,000 L	✅ Excellent – maintains crystal clarity
🏠 Medium In-Ground	50,000-76,000 L	✅ Good – suitable with 8-hour turnover
🏠 Large In-Ground	76,000+ L	⚠️ Consider FDB600 or FDB750 model

This Filter:

📍 Flow Rate: 9.5m³/h
📍 Optimal Pool Size: Up to 57,000 litres (6-hour turnover)
📍 Maximum Pool Size: Up to 76,000 litres (8-hour turnover)

💡 Tip: When in doubt, always size up. A slightly oversized filter reduces backwash frequency and improves water quality.

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🔌 Installation Requirements

Plumbing Connections:

Requirement	Specification
Inlet Connection	1½” (38mm)
Outlet Connection	1½” (38mm)
Valve Position	Side mount
Union Type	Standard threaded

Physical Installation:

Requirement	Details
Base	Solid, level concrete pad or paving recommended
Clearance Above	Minimum 400mm for valve operation and maintenance
Clearance Around	Minimum 300mm on all sides for access
Location	Protect from direct sunlight where possible

Pump Compatibility:

⚠️ Important: The filter must be paired with an appropriately sized pump to ensure optimal performance and longevity.

Parameter	Recommendation
Recommended Pump Flow	6.0 – 9.5m³/h
Maximum Pump Flow	Do not exceed 9.5m³/h
Pump Head	Match to system requirements

💡 Note: An undersized pump reduces filtration efficiency. An oversized pump can damage the filter media and internal components.

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🔄 Maintenance Guide

Routine Maintenance Schedule:

Task	Frequency	Method
Check pressure gauge	Weekly	Note baseline reading when clean
Backwash filter	When pressure rises 0.5-0.7 bar above clean baseline	Run until sight glass clears (typically 2-3 minutes)
Rinse after backwash	After every backwash	30-60 seconds to settle media
Inspect valve seals	Seasonally	Replace if worn or leaking
Check media level	Annually	Top up if low
Full media replacement	Every 5-7 years (sand)	Replace completely

Pressure Gauge Guide:

📊 Clean filter baseline: 0.8-1.0 bar (typical)
📊 Backwash recommended: 0.5-0.7 bar above baseline
📊 Maximum operating: 2.5 bar

⚠️ Warning: Never exceed the maximum working pressure of 2.5 bar. If pressure remains high after backwashing, inspect for blockages or consider media replacement.

Winterisation (Essential for UK Climate):

1. Switch off pump and allow system to depressurise
2. Set multiport valve to “Winterise” or between positions
3. Drain filter tank completely via manual drain
4. Remove and store drain plug safely
5. Leave multiport valve in intermediate position to prevent seal compression
6. Cover filter or relocate to frost-free storage if possible

⚠️ Critical: Never leave water in the filter during freezing conditions. Ice expansion can crack the tank and void warranty.

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🪨 Filter Media Information

The Certikin FDB500’s deep bed design is optimised for use with graded filter media, providing enhanced particle capture through its extended bed depth.

Recommended Media Configuration:

Layer	Media Type	Size	Purpose
Support Layer	Gravel	3.5mm	Supports sand bed, aids water distribution
Filtration Layer	Filter Sand	0.35-0.5mm	Primary filtration medium

Compatible Media Types:

Media Type	Filtration Rating	Lifespan	Benefits
Silica Sand	20-40 microns	5-7 years	Economical, proven performance
Glass Media	5-15 microns	10+ years	Finer filtration, longer life, eco-friendly
ZeoSand	3-5 microns	5 years	Superior clarity, reduced chemical demand

Media Capacity: 195kg total

💡 Professional Tip: Using a graded bed of gravel and sand is established practice for deep bed filters. This configuration assists both filtration and backwashing cycles for optimal performance.

Signs Media Needs Replacing:

• Persistently cloudy water despite correct chemical balance
• Shortened filter cycles requiring frequent backwashing
• Visible media in pool returns
• Media channelling or clumping

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🔬 Filtration Performance

Metric	Value
Filtration Rating (Sand)	20-40 microns
Filtration Rating (Glass)	5-15 microns
Filter Area	0.19m²
Design Flow Rate	9.5m³/h
Deep Bed Advantage	Extended contact time for superior particle capture

Micron Rating Guide:

Rating	What It Removes
40+ microns	Visible debris, leaves, large particles
20-40 microns	Sand, dirt, visible suspended particles
10-20 microns	Fine particles, some algae spores
5-10 microns	Very fine particles, most algae, cloudiness
Below 5 microns	Near invisible particles, bacteria

The FDB500’s deep bed design ensures water remains in contact with filter media significantly longer than standard depth filters, trapping finer particles and increasing overall dirt holding capacity. This translates to clearer water and longer intervals between backwashes.

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⚙️ Valve Positions & Functions

The included 6-way multiport valve provides complete control over all filtration and maintenance operations:

Position	Function	When to Use
Filter	Normal filtration mode	Daily operation – water flows through media and returns to pool
Backwash	Reverses flow to clean media	When pressure rises 0.5-0.7 bar above baseline
Rinse	Settles media after backwash	30-60 seconds after every backwash cycle
Waste	Bypasses filter, drains to waste	Vacuuming heavy debris, lowering water level
Recirculate	Bypasses filter, returns to pool	Distributing chemicals, troubleshooting
Closed	Stops all water flow	Maintenance, winterisation

⚠️ Important: Always switch off the pump before changing valve positions. Moving the valve under pressure can damage internal components and void warranty.

🎯 Ideal Applications

Application	Pool Size	Suitability
🏠 Residential Above-Ground	20,000-60,000 L	✅ Excellent
🏠 Residential In-Ground	Up to 76,000 L	✅ Very Good
🏡 Garden Pools	Up to 57,000 L	✅ Ideal
🧖 Large Swim Spas	8,000-15,000 L	✅ Premium Choice
🏢 Small Commercial	Not Recommended	❌ Consider FDB750 or commercial range

Recommended For:

• Pool owners seeking superior water clarity
• High-use residential pools requiring extended dirt capacity
• Upgrades from standard depth filters
• Installations where reduced backwash frequency is important
• Pools in areas with higher environmental debris loading

❓ Frequently Asked Questions

Q: What size pool will this filter handle? A: The FDB500 is suitable for pools up to 76,000 litres with an 8-hour turnover, or optimally up to 57,000 litres with a 6-hour turnover. The 9.5m³/h flow rate provides excellent filtration for medium to large residential pools.

Q: How often do I need to backwash? A: Backwash when the pressure gauge reads 0.5-0.7 bar above your clean baseline reading, typically every 1-2 weeks during swimming season. The deep bed design extends intervals compared to standard filters.

Q: What filter media should I use? A: The FDB500 is compatible with silica sand (0.35-0.5mm), glass media, or zeolite. Certikin recommends a graded bed using 3.5mm gravel as a support layer beneath the main filter sand. Total media capacity is 195kg.

Q: How long does filter media last? A: Silica sand typically lasts 5-7 years, while glass media can last 10+ years. ZeoSand has a similar lifespan to sand but offers finer filtration. Always replace media if water clarity cannot be maintained.

Q: What pump do I need? A: Pair with a pump delivering between 6.0-9.5m³/h. Never exceed the filter’s maximum flow rate of 9.5m³/h as this can damage media and reduce filtration efficiency.

Q: Is the multiport valve included? A: Yes, the FDB500 comes complete with a side-mounted 6-way multiport valve with 1½” connections, pressure gauge, manual air vent, and manual water drain – ready for installation.

Q: What warranty is included? A: Certikin products are backed by manufacturer warranty. Contact Parts4Tubs for full warranty terms and conditions applicable to your installation.

Q: Can I use glass media instead of sand? A: Absolutely. Glass media provides finer filtration (5-15 microns versus 20-40 microns for sand), lasts longer, and requires less frequent backwashing. It’s an excellent upgrade for the FDB500.

Q: What is the advantage of a deep bed filter? A: The extended media depth provides longer contact time between water and filter media, capturing finer particles and holding more dirt before backwashing is required. This results in clearer water and reduced maintenance.

🏆 Why Choose the Certikin FDB500

✅ Enhanced Filtration Performance – Deep bed design captures finer particles than standard filters, delivering noticeably clearer water

✅ Premium Build Quality – Bobbin-wound fibreglass construction from one of the UK’s most trusted pool equipment manufacturers

✅ Reduced Maintenance – Greater dirt holding capacity means longer intervals between backwashes

✅ Complete Package – Filter arrives with multiport valve, pressure gauge, and fittings pre-installed

✅ Versatile Media Options – Compatible with sand, glass, or zeolite media for customised filtration

✅ Perfect Size for UK Pools – 500mm diameter suits the majority of residential UK pool installations

✅ Proven Reliability – Certikin has been the UK’s leading pool equipment supplier for over 50 years

✅ Excellent Value – Professional-grade deep bed filtration at an accessible price point

🤝 Why Buy From Parts4Tubs

✅ UK-Based Company – Local support and expertise you can rely on

✅ Fast UK Delivery – Quick despatch to get your pool up and running

✅ Expert Advice – Our team understands pool filtration and can help with sizing and installation queries

✅ Competitive Pricing – Great value on genuine Certikin equipment

✅ Full Warranty Support – We stand behind every product we sell

✅ Easy Returns – Hassle-free 30-day returns policy

✅ Complete Range – Filter media, spare parts, and accessories all available

💫 Summary

The Certikin FDB500 Deep Bed Sand Filter delivers professional-grade filtration performance for residential pools up to 76,000 litres. Featuring a robust 500mm fibreglass tank, 9.5m³/h flow rate, and 195kg media capacity, this deep bed design provides superior water clarity through extended filtration contact time. Complete with side-mount 6-way multiport valve, pressure gauge, and 1½” connections, the FDB500 arrives ready for installation. An excellent choice for pool owners seeking enhanced filtration, reduced maintenance, and the reliability of Certikin’s UK-trusted quality.