🌊 Calplas DCH-415 Commercial Sand/AFM Pool Filter – Industrial-Grade Filtration for Pools up to 31,000 Litres

Handcrafted European engineering delivering exceptional water clarity for demanding commercial and large residential applications.

💧 Product Overview

The Calplas DCH-415 is an industrial-quality commercial pool filter engineered for superior filtration performance in demanding aquatic environments. Manufactured in Spain by Calplas, a company renowned for crafting premium pool vessels since 1970, this 415mm diameter filter combines traditional hand-laminated construction with modern filtration technology.

Built from glass-fibre reinforced polyester (GRP), the DCH-415 features a high-bed design with a substantial 1200mm filter bed height, optimised specifically for AFM (Activated Filter Media) or traditional sand. The internal steel reinforcement ensures structural integrity under pressure, whilst the specialised diffuser prevents cratering and channelling for consistent filtration across the entire media bed.

This filter represents the entry point to Calplas’s prestigious DCH commercial series, offering professional-grade performance in a compact footprint suitable for larger residential pools, holiday lets, small hotel pools, and light commercial applications requiring reliable, low-maintenance filtration.

⭐ Key Features

• ✅ Industrial GRP Construction – Hand-laminated glass-fibre reinforced polyester with internal steel reinforcement for maximum durability and longevity
• ✅ 1200mm High Filter Bed – Deep media bed provides extended contact time for superior particle removal and water polishing
• ✅ AFM & Sand Compatible – Optimised diffuser system designed specifically for both AFM activated glass media and traditional filter sand
• ✅ 2.5 Bar Working Pressure – Commercial-grade pressure rating with 3.75 bar test pressure ensures safe operation under demanding conditions
• ✅ Lateral Access Manhole – ø305mm service manhole with metal cover enables easy media inspection and maintenance
• ✅ Integrated Sight Glass – Built-in sight glass for monitoring backwash water clarity without interrupting operation
• ✅ Temperature Resistant – Rated for continuous operation up to 40°C, suitable for heated pools and warm climates
• ✅ 2″ Female Thread Connections – Standard BSP threaded inlet/outlet connections integrated directly into the GRP body
• ✅ Transparent Top Lid – Includes 3/4″ female vent connection for air release during priming
• ✅ 5-Year Tank Warranty – Manufacturer-backed warranty demonstrates confidence in construction quality
• ✅ European Quality Standards – Manufactured and calculated according to EN 13121-3 pressure vessel standards
• ✅ Handcrafted Excellence – Each filter individually hand-laminated by skilled craftsmen in Spain

🔧 Technical Specifications

Specification	Value
Model	DCH-415
Reference Code	1519260241 / 212341
Filter Type	High-Bed Sand/AFM Vertical Filter
Tank Diameter	415 mm
Total Height	1801 mm
Filter Bed Height	1200 mm
Filter Area	0.13 m²
Flow Rate (Filtration @ 30 m³/h/m²)	3.9 m³/hr
Flow Rate (Backwash @ 50 m³/h/m²)	6.5 m³/hr
Working Pressure	2.5 bar
Test Pressure	3.75 bar
Maximum Temperature	40°C
Inlet/Outlet Connections	2″ Female BSP (GAS thread)
Top Opening	ø190 mm
Service Manhole	ø305 mm
Distance from Ground (A)	260 mm
Connection Spacing (B)	1261 mm
Tank Material	GRP (Glass-Fibre Reinforced Polyester)
Internal Reinforcement	Steel reinforced walls
Colour	Blue RAL 5015 (White available on request)
Weight (Empty)	53 kg
Top Lid	Transparent with 3/4″ female vent
Sight Glass	Included as standard
Certification	EN 13121-3
Warranty	5 Years (Tank)

⚠️ Note: Pressure gauge, vent valve, and backwash valve/pipework sold separately.

📐 Pool Sizing Guide

Sizing Principle: The filter’s flow rate should achieve complete pool water turnover within 6-8 hours for optimal filtration and water quality.

Formula:

Pool Volume (litres) = Flow Rate (m³/hr) × Turnover Time (hours) × 1000

This Filter’s Capacity:

Turnover Time	Maximum Pool Volume
6 hours (Optimal)	23,400 litres
8 hours (Maximum)	31,200 litres

Pool Size Compatibility:

Pool Type	Volume Range	Suitability
🏊 Small above-ground	Up to 20,000 L	✅ Excellent – plenty of capacity headroom
🏊 Medium above-ground	20,000-30,000 L	✅ Very Good – ideal sizing range
🏠 Small in-ground	Up to 25,000 L	✅ Excellent – perfect match
🏠 Medium in-ground	25,000-31,000 L	✅ Good – at maximum capacity
🏢 Small commercial	20,000-31,000 L	✅ Good – with appropriate turnover

📍 Recommended Pool Size: Up to 31,000 litres with 8-hour turnover, or up to 23,400 litres for optimal 6-hour turnover.

💡 Pro Tip: For commercial applications or pools with high bather loads, sizing for 6-hour turnover is strongly recommended to maintain superior water quality.

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🛠️ Installation Requirements

Plumbing Connections:

Requirement	Specification
Inlet Connection	2″ Female BSP (GAS thread)
Outlet Connection	2″ Female BSP (GAS thread)
Vent Connection	3/4″ Female (on transparent lid)
Valve Type	Customer supplied (manual or automatic multiport)

Physical Installation:

Requirement	Details
Base	Solid, level concrete pad or compacted hardcore
Minimum Clearance Above	500 mm for lid removal and media loading
Minimum Clearance Around	400 mm for valve operation and maintenance
Ground Clearance	260 mm (integrated legs)
Access to Manhole	Ensure clear access to ø305 mm service manhole

Pump Compatibility:

Parameter	Requirement
Minimum Flow Rate	2.5 m³/hr
Optimal Flow Rate	3.0 – 3.9 m³/hr
Maximum Flow Rate	3.9 m³/hr (filtration) / 6.5 m³/hr (backwash)

⚠️ Important: The pump must be capable of delivering adequate backwash flow (up to 6.5 m³/hr) for effective media cleaning. Undersized pumps may result in insufficient backwashing.

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🔄 Maintenance Guide

Routine Maintenance Schedule:

Task	Frequency	Procedure
Check pressure gauge	Weekly	Record baseline and monitor for increases
Backwash filter	When pressure rises 0.3-0.5 bar above baseline	Backwash until sight glass runs clear (typically 2-3 minutes)
Rinse after backwash	After every backwash	Run rinse cycle for 30-60 seconds to settle media
Inspect manhole seals	Annually	Check for wear, replace if deteriorated
Check media level	Annually	Top up if settling has occurred
Full media replacement	Every 5-7 years (sand) / 10+ years (AFM)	Replace entire media bed

Pressure Gauge Guidelines:

Reading	Status
0.5 – 0.8 bar	Clean filter baseline (typical)
Baseline + 0.3 bar	Consider backwashing soon
Baseline + 0.5 bar	Backwash required
Above 2.0 bar	Investigate – possible blockage or pump issue

Winterisation (UK Climate):

1. ❄️ Turn off pump and close inlet/outlet valves
2. ❄️ Set multiport valve to “Winterise” or between positions
3. ❄️ Remove drain plug and drain all water from tank completely
4. ❄️ Store drain plug safely – leave drain open over winter
5. ❄️ If possible, cover filter or move to frost-free location
6. ❄️ Never leave standing water in the filter during freezing conditions

⚠️ Warning: Water left in the filter tank can freeze and crack the GRP shell, voiding warranty.

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🪨 Filter Media Information

The Calplas DCH-415 is optimised for high-bed filtration and designed to work with either traditional filter sand or AFM (Activated Filter Media).

Compatible Media Types:

Media Type	Filtration Rating	Lifespan	Key Benefits
Filter Sand (0.4-0.8mm)	20-40 microns	5-7 years	Economical, widely available, proven performance
AFM Grade 1 (0.5-1.0mm)	5-10 microns	10+ years	Superior filtration, self-sterilising, prevents biofilm
AFM Grade 2 (1.0-2.0mm)	Support layer	10+ years	Used beneath Grade 1 for optimal performance
Glass Media	15-20 microns	8-10 years	Better than sand, economical alternative to AFM

Media Capacity (from Manufacturer):

Media Configuration	Quantity
AFM (Recommended)	G3: 0 bags / G2: 3 bags / G1: 6 bags (21 kg bags)
Total AFM Weight	Approximately 189 kg
Sand Alternative	Grade-specific quantities as per manufacturer filling plan

💡 Recommendation: For optimal performance with this high-bed commercial filter, AFM is strongly recommended. The 1200mm bed height combined with AFM’s superior filtration properties delivers exceptional water clarity down to 1 micron.

Signs Media Needs Replacing:

• 🔍 Cloudy water despite correct chemical balance
• 🔍 Short filter cycles between backwashes
• 🔍 Media visible in pool returns
• 🔍 Excessive backwash water consumption
• 🔍 Inability to reach baseline pressure after backwash

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🔬 Filtration Performance

Metric	With Sand	With AFM
Filtration Rating	20-40 microns	1-5 microns
Filter Area	0.13 m²	0.13 m²
Flow Rate (Filtration)	3.9 m³/hr	3.9 m³/hr
Particle Removal Efficiency	70-80%	95%+

What Different Micron Ratings Capture:

Rating	Particles Removed
40+ microns	Visible debris, leaves, large particles
20-40 microns	Sand, dirt, most visible particles
10-20 microns	Fine particles, pollen, some algae
5-10 microns	Very fine particles, most algae, bacteria clumps
1-5 microns	Ultra-fine particles, single-celled algae, most bacteria

The DCH-415’s 1200mm high bed provides extended water contact time, maximising particle capture regardless of media type. When charged with AFM, this filter delivers commercial-grade filtration performance typically found in public swimming facilities.

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⚙️ Valve Positions & Functions

The DCH-415 requires a customer-supplied multiport valve or manual valve assembly. When fitted with a standard 6-way multiport valve, the following functions are available:

Position	Function	When to Use
Filter	Normal filtration mode	Standard daily operation
Backwash	Reverses flow to clean media	When pressure rises 0.3-0.5 bar above baseline
Rinse	Settles media, flushes to waste	After every backwash cycle
Waste	Bypasses filter, direct to drain	Vacuuming heavy debris, lowering water level
Recirculate	Bypasses filter, returns to pool	When adding chemicals, heating without filtering
Closed	Stops all water flow	Pump servicing, winterisation

⚠️ Never operate the pump with the valve in the “Closed” position – this will damage the pump.

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🏆 Ideal Applications

Application	Pool Size	Suitability
🏠 Large residential in-ground	Up to 31,000 L	✅ Excellent – premium residential filtration
🏡 Holiday let / rental pool	Up to 30,000 L	✅ Excellent – robust, low maintenance
🏨 Small hotel/B&B pool	Up to 25,000 L	✅ Very Good – commercial-grade reliability
🏊 Swimming school (small)	Up to 20,000 L	✅ Excellent – handles high bather loads
🏠 Heated indoor pool	Up to 30,000 L	✅ Excellent – rated to 40°C
💧 Spa overflow pool	Up to 25,000 L	✅ Good – handles warm water applications

❓ Frequently Asked Questions

Q: What size pool will this filter handle? A: The DCH-415 is suitable for pools up to 31,000 litres with an 8-hour turnover, or 23,400 litres for optimal 6-hour turnover. The 3.9 m³/hr flow rate handles most medium-sized residential and small commercial pools effectively.

Q: How often do I need to backwash? A: Backwash when the pressure gauge reads 0.3-0.5 bar above your clean baseline reading, typically every 1-2 weeks depending on pool usage and debris loading. Backwash until the sight glass runs clear.

Q: What filter media should I use? A: The DCH-415 is optimised for AFM (Activated Filter Media) or traditional filter sand. AFM is recommended for superior filtration down to 1 micron and a 10+ year lifespan. Media capacity is approximately 189 kg of AFM or equivalent sand.

Q: How long does filter media last? A: Sand typically requires replacement every 5-7 years. AFM lasts 10+ years with proper maintenance, making it more cost-effective long-term despite higher initial cost.

Q: What pump do I need? A: Match with a pump delivering 3.0-3.9 m³/hr for filtration. Ensure the pump can also achieve 6.5 m³/hr for effective backwashing. Do not exceed the filter’s maximum flow rates.

Q: Does this filter come with a multiport valve? A: No, the backwash valve/front tube system is sold separately. You can choose between automatic or manual valve options to suit your installation requirements.

Q: Is this filter suitable for saltwater pools? A: Yes, the GRP construction is resistant to saltwater corrosion. However, ensure all associated valves and pipework are also salt-compatible.

Q: What warranty is included? A: Calplas provides a 5-year tank warranty covering manufacturing defects in the GRP vessel. Contact Parts4Tubs for full warranty terms and conditions.

Q: Why is there a 4-6 week delivery time? A: Each Calplas DCH filter is hand-laminated to order in Spain, ensuring exceptional quality control. This made-to-order approach means your filter is crafted specifically for you.

Q: Can ozone be used with this filter? A: Standard models are not ozone-resistant. Ozone-compatible versions are available on request – please contact Parts4Tubs to discuss your requirements.

🏆 Why Choose the Calplas DCH-415

• ✅ European Craftsmanship – Hand-laminated in Spain by skilled technicians with over 50 years of manufacturing expertise
• ✅ Commercial-Grade Performance – 2.5 bar working pressure and steel-reinforced construction built for demanding applications
• ✅ Superior Filtration Capacity – 1200mm high bed delivers extended contact time for exceptional water clarity
• ✅ AFM Optimised Design – Purpose-built diffuser system maximises AFM performance for sub-5 micron filtration
• ✅ Long-Term Value – 5-year tank warranty and 10+ year media life with AFM minimises total cost of ownership
• ✅ Versatile Applications – Suitable for heated pools, saltwater systems, and light commercial use
• ✅ Low Maintenance – Robust construction and quality materials reduce servicing requirements
• ✅ Proven Reliability – Calplas filters trusted in industrial projects worldwide since 1970

🤝 Why Buy from Parts4Tubs

• ✅ UK-based company with knowledgeable local support
• ✅ Fast UK delivery on in-stock items
• ✅ Expert advice from pool and spa specialists
• ✅ Competitive pricing on Calplas commercial filters
• ✅ Full warranty support – we handle claims directly
• ✅ Easy returns within 30 days
• ✅ Compatible products available – AFM media, valves, pumps, and spare parts
• ✅ Made-to-order service – we coordinate directly with Calplas for your filter

✨ Summary

The Calplas DCH-415 delivers industrial-grade filtration in a compact 415mm diameter package, ideal for large residential pools and small commercial applications up to 31,000 litres. With its hand-laminated GRP construction, 1200mm high bed optimised for AFM, and 2.5 bar commercial pressure rating, this filter represents exceptional European engineering. The 5-year tank warranty, steel-reinforced internals, and compatibility with both sand and AFM media make it a versatile, long-term investment in water quality. Order today and experience the difference that over 50 years of Calplas craftsmanship delivers.