🌊 Certikin Hydroswim EHS520/T 20″ Top Mount Sand Filter with 1.5″ Multiport Valve – Up to 80,000 Litre Capacity

Powerful sand filtration for sparkling pool water, season after season

💧 Product Overview

The Certikin Hydroswim EHS520/T is a robust 20″ top mount sand filter engineered for reliable pool water filtration. Manufactured from high-quality laminated polyester with glass fibre reinforcement, this filter delivers excellent durability and corrosion resistance for years of dependable service.

Designed for domestic swimming pools up to 80,000 litres, the EHS520/T features a flow rate of 10 m³/hr and a generous 0.21 m² filtration area. The included 6-way multiport valve provides complete control over your filtration system, allowing you to filter, backwash, rinse, recirculate, drain to waste, or close the system with a simple turn of the handle.

The distinctive yellow housing combines practical functionality with a clean aesthetic. Complete with pressure gauge, air bleed system, and large bolt-down lid for easy maintenance access, this filter represents outstanding value for pool owners seeking reliable, professional-grade filtration equipment.

✨ Key Features

✅ Laminated Polyester Construction – Durable polyester resin and glass fibre tank offers excellent corrosion resistance and long service life

✅ 20″ (520mm) Tank Diameter – Compact footprint ideal for domestic pool installations with limited plant room space

✅ 10 m³/hr Flow Rate – Efficient water circulation suitable for pools up to 80,000 litres with 8-hour turnover

✅ 6-Way Multiport Valve – Complete filtration control including filter, backwash, rinse, recirculate, waste, and closed positions

✅ Top Mount Configuration – Convenient valve access from above for easy operation and maintenance

✅ Integrated Pressure Gauge – Monitor filter performance and know exactly when backwashing is required

✅ Manual Air Bleed System – Easily release trapped air to maintain optimal filtration efficiency

✅ Large Bolt-Down Lid – Simple access for media inspection, top-up, or complete replacement

✅ 1.5″ Connections – Standard sizing for easy integration with existing pool plumbing systems

✅ 2.5 Bar Maximum Working Pressure – Robust construction tested to 4 bar for safety and reliability

✅ 2 Year Manufacturer Warranty – Peace of mind with Certikin’s standard warranty coverage

🔩 Technical Specifications

Specification	Value
Model Number	EHS520/T
Filter Type	Sand Filter
Mount Type	Top Mount
Tank Diameter	520 mm (20″)
Overall Height	1045 mm
Height to Valve	810 mm
Flow Rate	10 m³/hr
Filtration Area	0.21 m²
Filtration Velocity	50 m³/h/m²
Filtration Rating	20-40 microns (sand media)
Pool Capacity	Up to 80,000 litres (8-hour turnover)
Sand Media Capacity	75 kg
Gravel Capacity	25 kg
Inlet/Outlet Connections	1.5″ (38 mm)
Valve Type	6-Way Multiport
Recommended Operating Pressure	0.5-1.6 bar
Maximum Working Pressure	2.5 bar
Test Pressure	4 bar
Maximum Operating Temperature	50°C
Tank Material	Laminated Polyester (Glass Fibre Reinforced)
Weight (Empty)	17 kg
Colour	Yellow
Warranty	2 Years

📏 Pool Sizing Guide

The flow rate of your pool filter should be capable of turning over the entire pool volume within 6-8 hours for optimal water quality. This ensures all pool water passes through the filtration system multiple times per day.

Sizing Formula:

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

Pool Size Compatibility:

Pool Type	Volume Range	Suitability
🏊 Small Above-Ground	Up to 20,000 L	Excellent – fast turnover
🏊 Medium Above-Ground	20,000-40,000 L	Excellent – ideal sizing
🏊 Large Above-Ground	40,000-60,000 L	Very Good – 6-hour turnover
🏠 Small In-Ground	Up to 50,000 L	Excellent – 5-hour turnover
🏠 Medium In-Ground	50,000-80,000 L	Good – 8-hour turnover
🏠 Large In-Ground	80,000+ L	Consider larger model

This Filter:

📍 Flow Rate: 10 m³/hr

📍 Optimal Pool Size: 40,000-60,000 litres (6-hour turnover)

📍 Maximum Pool Size: 80,000 litres (8-hour turnover)

🛠️ Installation Requirements

Plumbing Connections:

Requirement	Specification
Inlet Connection	1.5″ (38 mm)
Outlet Connection	1.5″ (38 mm)
Valve Position	Top Mount
Connection Type	Threaded

Physical Installation:

Requirement	Details
Base	Solid, level concrete pad or paving required
Clearance Above	Minimum 500 mm for valve operation and lid removal
Clearance Around	Minimum 300 mm on all sides for maintenance access
Location	Frost-free area or winterise for UK climate

Pump Compatibility:

⚠️ Important: The filter must be correctly matched with an appropriate pump for optimal performance.

Parameter	Recommendation
Recommended Pump Flow Rate	8-10 m³/hr
Maximum Pump Flow Rate	Do not exceed 10 m³/hr
Pump Head	Consult pump curves for your installation

💡 Tip: An undersized pump will result in poor filtration, while an oversized pump can damage the filter media and reduce filtration quality. Contact Parts4Tubs for pump matching advice.

---

🔄 Maintenance Guide

Routine Maintenance Schedule:

Task	Frequency	Method
Check pressure gauge	Weekly	Note baseline pressure when filter is clean
Backwash filter	When pressure rises 0.5-1.0 bar above baseline	Run until sight glass shows clear water
Rinse after backwash	After every backwash	Run for 30-60 seconds to settle media
Inspect valve seals	Seasonally	Check for wear, replace if cracked or leaking
Check media level	Annually	Top up if level has dropped
Full media replacement	Every 5-7 years	Replace sand completely

Pressure Gauge Guide:

📊 Clean Filter Baseline: 0.5-0.8 bar (record your specific baseline)

📊 Backwash Required: When pressure rises 0.5-1.0 bar above your baseline

📊 Maximum Safe Pressure: 2.5 bar (do not exceed)

⚠️ Warning: If pressure exceeds 2.5 bar, stop the pump immediately and investigate the cause.

Backwash Procedure:

1. Switch off the pump
2. Turn multiport valve to BACKWASH position
3. Start the pump and run until sight glass shows clear water (typically 2-3 minutes)
4. Switch off the pump
5. Turn multiport valve to RINSE position
6. Start the pump and run for 30-60 seconds
7. Switch off the pump
8. Return multiport valve to FILTER position
9. Resume normal operation

Winterisation (UK Climate):

For UK installations, proper winterisation is essential to prevent frost damage:

• Drain the filter tank completely via the drain plug
• Remove and safely store the drain plug indoors
• Cover the filter or relocate to a frost-free location if possible
• Never leave water standing in the filter during freezing conditions
• Consider insulating exposed pipework

---

🪨 Filter Media Information

Compatible Media Types:

Media Type	Filtration Rating	Lifespan	Benefits
Silica Sand (16/30 Grade)	20-40 microns	5-7 years	Economical, reliable, widely available
Glass Media	5-15 microns	10+ years	Superior clarity, requires less backwashing
ZeoSand/Zeolite	3-5 microns	5 years	Excellent clarity, ammonia removal properties

Media Capacity for EHS520/T:

Media	Quantity Required
Filter Sand	75 kg
Supporting Gravel	25 kg

💡 Tip: When using glass media, you can typically use 15-20% less by weight compared to sand whilst achieving better filtration performance.

Signs Your Media Needs Replacing:

• Poor water clarity despite correct chemical balance
• Short filter cycles between backwashes
• Cloudy water returning to pool after filtration
• Sand or media particles appearing in pool
• Filter requires constant backwashing
• Pressure drops despite not backwashing

🔬 Filtration Performance

Performance Metric	Value
Filtration Rating (Sand)	20-40 microns
Filtration Rating (Glass)	5-15 microns
Filtration Area	0.21 m²
Filtration Velocity	50 m³/h/m²

Micron Rating Guide – What Your Filter Catches:

Micron Rating	What It Removes
40+ microns	Visible debris, leaves, large particles
20-40 microns	Sand, dirt, visible particles, hair
10-20 microns	Fine particles, some algae spores
5-10 microns	Very fine particles, most algae, improved clarity
Under 5 microns	Ultra-fine particles, bacteria-sized debris

💡 Performance Tip: As your sand filter accumulates a small amount of debris, filtration actually improves temporarily before requiring backwash. A slightly “seasoned” filter can trap particles in the 20-micron range, whilst a freshly backwashed filter may only achieve 40-micron filtration initially.

⚙️ Valve Positions & Functions

The 6-way multiport valve provides complete control over your filtration system:

Position	Function	When to Use
FILTER	Normal filtration operation	Daily operation
BACKWASH	Reverses water flow through media to flush debris to waste	When pressure rises 0.5-1.0 bar above baseline
RINSE	Settles media and flushes remaining debris after backwash	Always after backwashing (30-60 seconds)
WASTE	Bypasses filter, sends water directly to drain	Lowering water level, vacuuming heavy debris
RECIRCULATE	Bypasses filter media, returns water to pool	Distributing chemicals quickly
CLOSED	Stops all water flow through valve	Pump maintenance, winterisation

⚠️ Important: Always switch off the pump before changing valve position. Operating the valve under pressure can damage seals and internal components.

🎯 Ideal Applications

Application	Pool Size	Suitability
🏠 Residential Above-Ground Pool	Up to 60,000 L	Excellent
🏠 Residential In-Ground Pool	Up to 80,000 L	Very Good
🏡 Garden Swim Spa	Up to 20,000 L	Excellent (fast turnover)
🏊 Holiday Home Pool	Up to 60,000 L	Ideal
🏢 Small Commercial	Not recommended	Consider larger model

❓ Frequently Asked Questions

Q: What size pool will this filter handle? A: The EHS520/T is suitable for pools up to 80,000 litres with its 10 m³/hr flow rate, achieving an 8-hour turnover. For optimal water quality, we recommend pools up to 60,000 litres for a 6-hour turnover cycle.

Q: How often do I need to backwash? A: Backwash when your pressure gauge reads 0.5-1.0 bar above your clean filter baseline. This is typically every 1-2 weeks during the swimming season, though frequency varies with pool usage and environmental debris.

Q: What filter media should I use? A: The filter is compatible with standard pool filter sand (16/30 grade), glass media, or zeolite. Sand capacity is 75 kg with 25 kg supporting gravel. Glass media offers superior filtration down to 5-15 microns compared to sand’s 20-40 microns.

Q: How long does filter media last? A: Silica sand typically lasts 5-7 years with proper maintenance. Glass media can last 10+ years. Zeolite typically requires replacement every 5 years. Replace when you notice persistent water clarity issues despite proper chemical balance.

Q: What pump do I need? A: Match this filter with a pump delivering 8-10 m³/hr. The pump flow rate should not exceed 10 m³/hr to ensure proper filtration and prevent media damage. Contact Parts4Tubs for specific pump recommendations.

Q: What warranty is included? A: The Certikin Hydroswim EHS520/T comes with a 2-year manufacturer warranty. Contact Parts4Tubs for full warranty terms and conditions.

Q: Can I use this filter for a hot tub? A: Whilst technically compatible, the 10 m³/hr flow rate is higher than most hot tub applications require. A smaller cartridge filter is typically more appropriate for hot tubs. This filter is designed for swimming pool applications.

Q: How do I winterise this filter in the UK? A: Drain all water from the tank via the drain plug, remove and store the drain plug safely, and either cover the filter or move it to a frost-free location. Never allow water to remain in the filter during freezing temperatures.

Q: What is the filtration velocity and why does it matter? A: The filtration velocity of 50 m³/h/m² indicates how quickly water passes through the filter media. This is within the optimal range for effective sand filtration, balancing thorough particle removal with practical flow rates.

📥 Downloads & Resources

📄 Product Brochure & Technical Specifications – Complete Hydroswim filter range specifications

🏆 Why Choose the Certikin Hydroswim EHS520/T

✅ Proven Filtration Performance – 10 m³/hr flow rate with 0.21 m² filtration area delivers crystal clear pool water

✅ Robust Construction – Laminated polyester with glass fibre reinforcement built to withstand years of continuous use

✅ Simple Operation – 6-way multiport valve with clear positions makes daily operation straightforward

✅ Easy Maintenance – Large bolt-down lid provides convenient access for media inspection and replacement

✅ Flexible Media Options – Compatible with sand, glass, or zeolite media to suit your filtration preferences

✅ Comprehensive Warranty – 2-year Certikin manufacturer warranty for peace of mind

✅ Trusted Brand – Certikin has been supplying the UK pool industry for over 50 years

✅ Compact Footprint – Top mount design maximises vertical space efficiency in plant rooms

🤝 Why Buy from Parts4Tubs

✅ UK-Based Company – Local support from pool and spa specialists who understand UK requirements

✅ Fast UK Delivery – Quick dispatch to get your pool back in action

✅ Expert Advice – Technical guidance on sizing, installation, and compatibility

✅ Competitive Pricing – Great value on genuine Certikin products

✅ Full Warranty Support – We handle warranty claims efficiently on your behalf

✅ Easy Returns – 30-day returns policy for your peace of mind

✅ Complete Range – Filter media, replacement parts, and compatible pumps all available

✅ Established Business – Built on the success of buildahottub.com with years of industry experience

💧 Summary

The Certikin Hydroswim EHS520/T delivers reliable, professional-grade filtration for domestic swimming pools up to 80,000 litres. With its robust laminated polyester construction, efficient 10 m³/hr flow rate, and user-friendly 6-way multiport valve, this 20″ top mount sand filter offers excellent value for pool owners seeking dependable water clarity.

Complete with pressure gauge, air bleed system, and backed by Certikin’s 2-year warranty, the EHS520/T is ready to keep your pool water sparkling clean season after season. Order today for fast UK delivery.