🌊 Calplas DCH-520 Commercial High-Bed Sand Filter – 2″ Connections

Professional-grade filtration engineered for commercial pools and demanding residential installations

💧 Product Overview

The Calplas DCH-520 is an industrial-quality polyester sand filter designed specifically for commercial swimming pool applications. Featuring an impressive 1200mm filter bed height, this high-performance unit delivers exceptional water clarity through superior filtration depth that far exceeds standard residential filters.

Manufactured by Calplas, a world-renowned Spanish filter manufacturer with over 50 years of expertise since 1970, this filter features hand lay-up GRP (glass-reinforced polyester) construction with internal steel reinforcement for outstanding durability under commercial operating conditions. The 520mm diameter tank provides 0.20 m² of filter area, delivering flow rates up to 10 m³/h during backwash operations and 6 m³/h for standard filtration.

Ideal for small to medium commercial pools, spa facilities, holiday parks, and premium residential installations requiring professional-grade filtration performance.

✨ Key Features

✅ Industrial-Grade GRP Construction – Hand lay-up glass-reinforced polyester with internal steel reinforcement for exceptional strength and longevity

✅ 1200mm High Filter Bed – Extended depth filter bed delivers superior water polishing compared to standard filters (1500mm available on request)

✅ 0.20 m² Filter Area – Generous filtration surface for effective particle capture and extended backwash cycles

✅ 2″ Threaded Connections – Female GAS threads integrated directly into the filter body for leak-free installation

✅ Lateral Access Manhole – 305mm service manhole with metal cover for easy media inspection and replacement (transparent cover optional)

✅ Special AFM/Sand Diffuser – Top diffuser prevents crater formation and channelling for even water distribution across the filter bed

✅ Integrated Sight Glass – Monitor backwash water clarity without interrupting the process

✅ Temperature Resistant to 40°C – Suitable for heated pool applications (ozone resistance available on request)

✅ Commercial Pressure Rating – 2.5 bar maximum operating pressure with 3.75 bar test pressure

✅ 5 Year Tank Warranty – Comprehensive manufacturer warranty for peace of mind

⚙️ Technical Specifications

Specification	Value
Model	DCH-520
Product Code	1519260254 / 212352
Filter Type	High-Bed Sand/AFM Filter
Tank Diameter	520 mm
Tank Height	1832 mm
Filter Area	0.20 m²
Filter Bed Height	1200 mm (1500 mm available on request)
Flow Rate (Filtration @ 30 m³/h/m²)	6 m³/h
Flow Rate (Backwash @ 50 m³/h/m²)	10 m³/h
Working Pressure	2.5 bar
Test Pressure	3.75 bar
Inlet/Outlet Connection	2″ Female (GAS thread)
Filter Opening (Top)	ø 190 mm
Service Manhole	ø 305 mm
Distance from Ground (A)	300 mm
Distance Between Connections (B)	1237 mm
Tank Material	GRP (Glass-Reinforced Polyester) with steel reinforcement
Weight (Empty)	61 kg
Maximum Temperature	40°C
Colour	Blue RAL 5015 (white available on request)
Certifications	Manufactured according to EN 13121-3
Warranty	5 Years Tank Warranty

📏 Pool Sizing Guide

The Calplas DCH-520 delivers a filtration flow rate of 6 m³/h, making it ideal for pools requiring professional-grade water treatment.

Sizing Formula:

Pool Capacity = Flow Rate × Turnover Time

Turnover Time	Maximum Pool Capacity	Application
6 hours (optimal)	36,000 litres	Commercial pools, high bather loads
8 hours (standard)	48,000 litres	Private pools, moderate usage

Pool Size Compatibility:

Pool Type	Suitability	Notes
🏠 Large residential in-ground	✅ Excellent	Up to 48,000 L with 8-hour turnover
🏢 Small commercial pool	✅ Ideal	Up to 36,000 L with 6-hour turnover
🧖 Spa/wellness facilities	✅ Excellent	Superior filtration for crystal-clear water
🏨 Holiday park pools	✅ Recommended	Professional-grade reliability
🏊 Swim spas	✅ Excellent	High-capacity filtration

This Filter:

• 📍 Filtration Flow Rate: 6 m³/h
• 📍 Backwash Flow Rate: 10 m³/h
• 📍 Optimal for pools up to: 36,000 litres (6-hour turnover)
• 📍 Maximum recommended: 48,000 litres (8-hour turnover)

🛠️ Installation Requirements

Plumbing Connections

Requirement	Specification
Inlet Connection	2″ Female (GAS thread)
Outlet Connection	2″ Female (GAS thread)
Connection Position	Side-mounted
Connection Spacing (B)	1237 mm

Physical Installation

Requirement	Details
Base	Solid, level concrete pad required
Clearance Above	Minimum 500 mm for manhole access and valve operation
Clearance Around	Minimum 400 mm for maintenance access
Distance from Ground (A)	300 mm (built-in legs)

Pump Compatibility

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

Parameter	Specification
Recommended Pump Flow Rate	4 – 6 m³/h for filtration
Maximum Pump Flow Rate	Do not exceed 10 m³/h
Backwash Requirement	Pump capable of 10 m³/h for effective backwashing

💡 Tip: The pump flow rate should never exceed the filter’s maximum capacity. Oversized pumps can damage the filter media and compromise filtration quality.

🔄 Maintenance Guide

Routine Maintenance Schedule

Task	Frequency	Details
Check pressure gauge	Weekly	Note baseline pressure when clean
Backwash filter	When pressure rises 0.5-0.7 bar above baseline	Until sight glass shows clear water
Rinse after backwash	After every backwash	30-60 seconds to settle media
Inspect manhole seal	Seasonally	Replace O-ring if worn or damaged
Check media level	Annually	Top up if settlement occurs
Complete media replacement	Every 5-7 years (sand) / 10+ years (AFM)	Replace entire filter bed

Pressure Gauge Guide

Reading	Status
📊 Baseline (clean filter)	Record this reading after fresh backwash
📊 Backwash needed	0.5-0.7 bar above baseline
📊 Maximum safe pressure	2.5 bar

⚠️ Warning: Never operate the filter above 2.5 bar. If pressure remains high after backwashing, inspect for media channelling or consider media replacement.

Winterisation (UK Climate)

For outdoor installations or unheated plant rooms, proper winterisation is essential:

1. Fully drain the filter tank via the drain plug
2. Remove and safely store the drain plug
3. Leave multiport valve in the winterise position (if fitted)
4. Cover the filter or relocate to a frost-free environment
5. Never leave water in the filter during freezing conditions

⚠️ Frost damage is not covered under warranty

🪨 Filter Media Information

The Calplas DCH-520 is compatible with both traditional sand and advanced AFM® (Activated Filter Media) for superior filtration performance.

Media Requirements (per filter)

Media Type	Layer Configuration	Total Quantity
AFM®	G3: 0 bags / G2: 4 bags / G1: 10 bags	14 bags × 21 kg = 294 kg
Sand	2-3mm: 0 bags / 0.7-1.2mm: 4 bags / 0.4-0.8mm: 10 bags	14 bags × 25 kg = 350 kg

Media Comparison

Media Type	Filtration Rating	Lifespan	Benefits
Sand	20-40 microns	5-7 years	Economical, widely available
Glass (AFM®)	5-15 microns	10+ years	Finer filtration, self-sterilising, longer life
ZeoSand	3-5 microns	5 years	Superior clarity, ammonia reduction

💡 Recommendation: For commercial installations, AFM® glass media provides superior filtration and significantly longer service life, offering better long-term value despite higher initial cost.

Signs Media Needs Replacing

• Poor water clarity despite correct chemical balance
• Short filter cycles between backwashes
• Cloudy water returning to pool after filtration
• Media visible in pool (indicates damaged laterals)
• Increased chemical consumption

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💎 Filtration Performance

Metric	Value
Filter Area	0.20 m²
Filter Bed Height	1200 mm
Filtration Rating (Sand)	20-40 microns
Filtration Rating (AFM®)	5-15 microns

Micron Rating Guide

Rating	What It Captures
40+ microns	Visible debris, leaves, large particles
20-40 microns	Sand, dirt, visible suspended matter
10-20 microns	Fine particles, some algae spores
5-10 microns	Very fine particles, most algae, bacteria clusters

The 1200mm high filter bed provides extended contact time between water and media, resulting in superior particle capture compared to standard-depth filters.

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⚙️ Multiport Valve Functions

Note: Valve sold separately. Compatible with 2″ side-mount multiport valves.

Position	Function
Filter	Normal filtration – water flows through media to pool
Backwash	Reverses flow to flush debris from media to waste
Rinse	Settles media and clears pipework after backwash
Waste	Bypasses filter, sends water directly to drain
Recirculate	Bypasses filter, returns water to pool (for chemical distribution)
Closed	Stops all water flow
Winterise	Relieves pressure from all ports for winter storage

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🎯 Ideal Applications

Application	Pool Size	Suitability
🏠 Premium residential in-ground	Up to 48,000 L	✅ Excellent for demanding homeowners
🏢 Small commercial pools	Up to 36,000 L	✅ Designed for commercial duty
🧖 Spa and wellness centres	Various	✅ Superior water clarity
🏨 Hotel and holiday park pools	Up to 36,000 L	✅ Built for continuous operation
🏊 Hydrotherapy pools	Up to 36,000 L	✅ High-quality filtration essential
🏫 School and leisure centre pools	Up to 36,000 L	✅ Commercial-grade reliability

❓ Frequently Asked Questions

Q: What size pool will this filter handle? A: The DCH-520 is suitable for pools up to 36,000 litres with optimal 6-hour turnover, or up to 48,000 litres with 8-hour turnover. The 6 m³/h filtration flow rate delivers professional-grade water treatment.

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 depending on bather load and environmental factors. Always rinse for 30-60 seconds after backwashing.

Q: What filter media should I use? A: The filter is compatible with both sand and AFM® glass media. For commercial installations, we recommend AFM® for its finer filtration (5-15 microns vs 20-40 microns for sand) and extended 10+ year lifespan.

Q: How much filter media do I need? A: For sand: approximately 350 kg in layered grades. For AFM®: approximately 294 kg (14 bags × 21 kg). Contact Parts4Tubs for specific filling plans.

Q: What pump do I need? A: Match with a pump delivering 4-6 m³/h for filtration. The pump must be capable of 10 m³/h for effective backwashing. Never exceed the filter’s maximum flow rate.

Q: Is a multiport valve included? A: No, the backwash valve/front tube system is sold separately. The filter accepts 2″ side-mount multiport valves. Automatic and manual options are available.

Q: What is the delivery time? A: Calplas DCH filters are hand-made to order. Please allow 4-6 weeks delivery time. Contact Parts4Tubs for current lead times.

Q: What warranty is included? A: This filter comes with a 5 Year Tank Warranty from Calplas. Contact Parts4Tubs for full warranty terms and conditions.

Q: Can this filter handle heated pools? A: Yes, the DCH-520 is temperature resistant up to 40°C, making it suitable for heated swimming pools and spa installations. Ozone resistance is available on request.

📥 Downloads & Resources

📄 Calplas DCH Filter Datasheet – Complete specifications and dimensions

🏆 Why Choose the Calplas DCH-520

✅ Commercial-Grade Construction – Hand lay-up GRP with steel reinforcement built to withstand demanding commercial environments

✅ Superior Filtration Depth – 1200mm filter bed height delivers exceptional water polishing unmatched by standard filters

✅ World-Renowned Manufacturer – Calplas has been producing premium filters since 1970 with proven reliability worldwide

✅ Versatile Media Compatibility – Works with sand, AFM®, or zeolite for flexibility in filtration performance

✅ Professional Specifications – 2.5 bar working pressure and EN 13121-3 certification for commercial applications

✅ 5 Year Tank Warranty – Comprehensive warranty coverage demonstrates manufacturer confidence in build quality

✅ UK-Ready – Side-mounted 2″ connections compatible with standard UK pool equipment

🤝 Why Buy from Parts4Tubs

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

✅ Fast UK Delivery – Efficient shipping across the United Kingdom

✅ Expert Technical Advice – Our team can help with sizing, installation, and media selection

✅ Competitive Pricing – Trade and retail pricing on commercial equipment

✅ Full Warranty Support – We handle warranty claims directly with manufacturers

✅ Easy Returns – 30-day return policy on unused items

✅ Complete System Supply – Pumps, valves, media, and accessories all available

✨ Summary

The Calplas DCH-520 Commercial High-Bed Sand Filter delivers professional-grade filtration for pools up to 48,000 litres. Featuring industrial GRP construction with steel reinforcement, an impressive 1200mm filter bed depth, and 0.20 m² filter area, this hand-crafted filter provides exceptional water clarity for demanding commercial and premium residential applications. Backed by a 5 Year Tank Warranty and Calplas’s 50+ years of manufacturing expertise, it’s the reliable choice for installations where water quality matters.