🌊 Certikin Hydroswim EHS640/T 25″ Top Mount Sand Filter – For Pools Up To 90,000 Litres

Reliable filtration performance for medium to large residential pools, engineered for UK conditions.

💧 Product Overview

The Certikin Hydroswim EHS640/T is a robust 25-inch top mount sand filter designed to deliver exceptional water clarity for medium to large swimming pools. Manufactured from high-quality laminated polyester reinforced with glass fibre, this filter combines durability with outstanding filtration performance.

Featuring a powerful 15 m³/h flow rate and generous 0.32 m² filtration area, the EHS640/T efficiently handles pools up to 90,000 litres with a standard 6-hour turnover. The top mount configuration provides easy access to the filter media while the included 6-way multiport valve gives you complete control over all filtration operations.

With its striking yellow finish and professional-grade construction, this Certikin filter represents excellent value for pool owners seeking reliable, low-maintenance filtration from a trusted European manufacturer.

⭐ Key Features

✅ 25-Inch Tank Diameter – Large 640mm tank provides ample filtration capacity for medium to large residential pools

✅ 15 m³/h Flow Rate – High flow capacity ensures efficient water turnover for pools up to 90,000 litres

✅ Top Mount Design – Convenient valve position for easy operation and maintenance access

✅ 6-Way Multiport Valve – Complete control with Filter, Backwash, Rinse, Recirculate, Waste, and Closed positions

✅ 1.5-Inch Connections – Standard inlet/outlet size for compatibility with most pool plumbing systems

✅ Laminated Polyester Construction – Durable glass fibre reinforced body resists corrosion and UV damage

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

✅ Manual Air Bleed Valve – Easily release trapped air for optimal filter performance

✅ Large Bolt-Down Lid – Quick access to filter media for inspection and replacement

✅ 100kg Sand Capacity – Generous media capacity for extended filtration cycles between backwashes

✅ 2.5 Bar Maximum Pressure – Rigorously tested to 4 bar for 20,000 cycles ensuring long-term reliability

🔧 Technical Specifications

Specification	Value
Filter Type	Sand Filter
Model	EHS640/T
Mount Type	Top Mount
Tank Diameter	640 mm (25″)
Total Height	1115 mm
Height to Valve	880 mm
Flow Rate	15 m³/h
Filtration Area	0.32 m²
Filtration Velocity	50 m³/h/m²
Filtration Rating	20-40 microns (with sand media)
Sand Capacity	100 kg
Gravel Capacity	50 kg
Inlet/Outlet Size	1.5″ (38 mm)
Valve Type	6-Way Multiport
Working Pressure	0.5 – 1.6 bar (recommended)
Maximum Pressure	2.5 bar
Test Pressure	4 bar (20,000 cycles)
Maximum Temperature	50°C
Tank Material	Laminated Polyester (Glass Fibre Reinforced)
Weight (Empty)	22 kg
Colour	Yellow
Included Features	Pressure gauge, air bleed, large bolt-down lid

📏 Pool Sizing Guide

The key to effective pool filtration is ensuring your filter can turn over the entire pool volume within the recommended timeframe.

Sizing Principle: Your filter’s flow rate should be capable of circulating the entire pool volume in 6-8 hours for residential pools.

Formula:

Maximum Pool Volume = Flow Rate (m³/h) × Turnover Time (hours)

This Filter’s Capacity:

Turnover Time	Maximum Pool Volume
6 hours (recommended)	90,000 litres
7 hours	105,000 litres
8 hours	120,000 litres

Pool Size Compatibility:

Pool Type	Volume Range	Suitability
🏊 Medium above-ground	20,000 – 40,000 L	Excellent – generous capacity
🏊 Large above-ground	40,000 – 60,000 L	Excellent – ideal match
🏠 Small in-ground	Up to 50,000 L	Excellent – ample filtration
🏠 Medium in-ground	50,000 – 80,000 L	Very Good – efficient turnover
🏠 Large in-ground	80,000 – 90,000 L	Good – meets 6-hour turnover

This Filter:

📍 Flow Rate: 15 m³/h
📍 Suitable for pools up to: 90,000 litres (with 6-hour turnover)

🛠️ Installation Requirements

Plumbing Connections

Requirement	Specification
Inlet Connection	1.5″ (38 mm)
Outlet Connection	1.5″ (38 mm)
Valve Position	Top mount

Physical Installation

Requirement	Details
Base	Solid, level concrete pad or paving required
Clearance Above	Minimum 500 mm recommended for valve operation and lid removal
Clearance Around	Minimum 300 mm for maintenance access
Location	Sheltered area recommended; protect from direct weather exposure

Pump Compatibility

⚠️ Important: The filter must be matched with an appropriately sized pump.

Pump Requirement	Specification
Recommended Flow Rate	12 – 15 m³/h
Maximum Flow Rate	15 m³/h
Minimum for Backwash	12 m³/h (for effective media cleaning)

💡 Tip: Ensure your pump’s maximum output does not exceed the filter’s rated flow capacity to prevent damage and maintain optimal filtration.

🔄 Maintenance Guide

Routine Maintenance Schedule

Task	Frequency	How To
Check pressure gauge	Weekly	Record baseline; note any changes
Backwash filter	When pressure rises 0.5-0.8 bar above baseline	Typically every 1-2 weeks
Rinse after backwash	After each backwash	Run for 30-60 seconds
Inspect O-rings and seals	Every 3 months	Replace if worn or cracked
Check media level	Annually	Top up if settled below recommended level
Full media replacement	Every 5-7 years (sand)	Replace with fresh filter sand

Pressure Gauge Guide

📊 Clean filter baseline: 0.5 – 0.8 bar
📊 Backwash needed: When pressure rises 0.5 – 0.8 bar above your baseline
📊 Maximum operating pressure: 2.5 bar

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

Winterisation (UK Climate)

Proper winterisation is essential for UK pool owners to prevent frost damage:

1. Drain the filter tank completely via the drain plug
2. Remove and store the drain plug in a safe place
3. Set multiport valve to Winter position or between settings to prevent seal damage
4. Cover or store the filter in a frost-free location if possible
5. Never leave water in the filter during freezing conditions

💡 Tip: Adding a weatherproof filter cover can extend the life of your equipment when left outdoors during winter.

🪨 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, proven performance
Glass Media	5-15 microns	10+ years	Finer filtration, eco-friendly, lighter weight
ZeoSand/Zeolite	3-5 microns	5 years	Superior water clarity, ammonia removal
Filter Balls	10-15 microns	3-4 years	Ultra-lightweight, easy to handle

Media Requirements for EHS640/T

Media	Quantity Required
Filter Sand	100 kg
Support Gravel	50 kg

💡 Note: When using glass media, you can typically use 15-20% less by weight compared to sand.

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 pressure remains high even after backwashing

🔬 Filtration Performance

Metric	Value
Filtration Rating	20-40 microns (with standard sand)
Filtration Area	0.32 m²
Filtration Velocity	50 m³/h/m²
Flow Rate	15 m³/h

Micron Rating Guide

Understanding what your filter can capture:

Rating	What It Removes
40+ microns	Visible debris, leaves, large insects
20-40 microns	Sand, dirt, visible particles, hair
10-20 microns	Fine particles, some algae spores
5-10 microns	Very fine particles, most algae, pollen

💡 Upgrade Tip: Switching from sand to glass media can improve your filtration from 20-40 microns down to 5-15 microns for noticeably clearer water.

⚙️ Valve Positions & Functions

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

Position	Function	When to Use
Filter	Normal filtration mode	Daily operation – water flows through media and returns clean to pool
Backwash	Reverses flow to flush debris from media	When pressure gauge reads 0.5-0.8 bar above baseline
Rinse	Settles and compacts media after backwash	Always run for 30-60 seconds after backwashing
Waste	Bypasses filter, sends water to drain	Vacuuming heavy debris, lowering water level
Recirculate	Bypasses filter, returns water to pool	Distributing chemicals quickly without filtering
Closed	Stops all water flow through valve	Equipment maintenance, pump servicing

⚠️ Important: Never change valve position while the pump is running. Always switch off the pump first.

🎯 Ideal Applications

Application	Pool Size	Suitability
🏠 Residential above-ground pools	20,000 – 60,000 L	Excellent
🏠 Residential in-ground pools	Up to 90,000 L	Excellent
🏊 Large family pools	60,000 – 90,000 L	Very Good
🏡 Holiday home/rental pools	Up to 80,000 L	Excellent

❓ Frequently Asked Questions

Q: What size pool will this filter handle?

A: The Certikin Hydroswim EHS640/T is suitable for pools up to 90,000 litres with a 6-hour turnover, or up to 120,000 litres with an 8-hour turnover. For optimal water clarity, we recommend sizing for a 6-hour turnover.

Q: How often do I need to backwash?

A: Backwash when your pressure gauge reads 0.5-0.8 bar above the clean baseline pressure. This is typically every 1-2 weeks during the swimming season, but frequency depends on pool usage, bather load, and environmental factors.

Q: What filter media should I use?

A: The filter is compatible with standard pool sand (#16/30 silica sand), glass media, ZeoSand, or filter balls. Sand capacity is 100 kg plus 50 kg of support gravel. Glass media offers finer filtration if upgrading from sand.

Q: How long does the filter media last?

A: Standard sand media typically lasts 5-7 years before requiring replacement. Glass media can last 10+ years. ZeoSand and filter balls typically last 3-5 years.

Q: What pump do I need with this filter?

A: Match with a pump delivering 12-15 m³/h. The pump flow rate should not exceed 15 m³/h to prevent damage. Ensure the pump can also deliver sufficient flow for effective backwashing.

Q: What is the maximum working pressure?

A: The maximum working pressure is 2.5 bar. The filter has been tested at 4 bar for 20,000 cycles to ensure long-term reliability. Recommended operating pressure is 0.5-1.6 bar.

Q: Can I use this filter with saltwater pools?

A: Yes, the laminated polyester construction is resistant to saltwater corrosion. Ensure all connections and O-rings are also saltwater compatible.

Q: What warranty is included?

A: Please contact Parts4Tubs directly for full warranty terms and conditions on Certikin products.

📥 Downloads & Resources

📄 Hydroswim Product Brochure – Full specifications and technical data

🏆 Why Choose the Certikin Hydroswim EHS640/T

✅ Proven Filtration Performance – 15 m³/h flow rate handles pools up to 90,000 litres efficiently

✅ Durable Construction – Laminated polyester with glass fibre reinforcement resists corrosion and UV damage

✅ Easy Maintenance – Top mount design with large bolt-down lid provides quick access to filter media

✅ Complete Control – 6-way multiport valve covers all filtration operations

✅ Reliable Pressure Rating – Tested at 4 bar for 20,000 cycles; 2.5 bar maximum working pressure

✅ Trusted Brand – Certikin is a leading European pool equipment manufacturer with decades of expertise

✅ Generous Media Capacity – 100 kg sand capacity means longer cycles between backwashes

✅ UK Climate Ready – Designed to withstand British weather conditions when properly winterised

🤝 Why Buy From Parts4Tubs

✅ UK-Based Company – Local support from Northamptonshire

✅ Fast UK Delivery – Quick dispatch to get your pool running

✅ Expert Advice – Specialist knowledge from pool and spa professionals

✅ Competitive Pricing – Great value on quality pool equipment

✅ Full Warranty Support – We stand behind the products we sell

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

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

✨ Summary

The Certikin Hydroswim EHS640/T is a reliable, high-capacity 25-inch top mount sand filter ideal for medium to large residential pools up to 90,000 litres. With its 15 m³/h flow rate, durable laminated polyester construction, and convenient 6-way multiport valve, this filter delivers consistent water clarity with minimal maintenance. Complete with pressure gauge, air bleed valve, and generous 100 kg sand capacity, it represents excellent value for UK pool owners seeking dependable, long-lasting filtration performance.