🌊 Calplas AFM/P-960 Side Mount Pool Filter – Up to 168,000 Litre Capacity

The flagship semi-high bed filter for large commercial pools and demanding installations.

💧 Product Overview

The Calplas AFM/P-960 is the flagship model in the AFM/P range, delivering exceptional filtration capacity for large commercial pools and demanding high-volume installations. Featuring an impressive 960mm diameter tank constructed from hand-laid glass fibre reinforced polyester (GRP), this professional-grade filter represents the pinnacle of Calplas engineering with its substantial 0.70 m² filter area.

With 3.5 times the filter area of the entry-level 520mm model and a robust 900mm filter bed height, the AFM/P-960 handles pools up to 168,000 litres with exceptional efficiency. The extended media depth ensures outstanding contact time between water and filter media, delivering superior water clarity whether using traditional sand or advanced AFM® activated glass media.

Manufactured in Spain by Calplas according to EN 13121-3 European standards, this filter is the ultimate choice for commercial swimming pools, leisure centres, hotels, and large estate pools where reliable, high-volume filtration is essential. Enhanced features include larger 2½” connections for reduced pressure loss, an extra-large 355mm service manhole, and compatibility with the Besgo automatic backwash valve system for hands-free operation in busy commercial environments.

⭐ Key Features

• ✅ Flagship Capacity – 0.70 m² filter area delivers maximum filtration power in the AFM/P range
• ✅ Semi-High Bed Design – 900mm filter bed height provides superior contact time for exceptional water clarity
• ✅ Larger 2½” Connections – Upgraded connection size reduces pressure loss for improved system efficiency
• ✅ Extra-Large Service Manhole – ø 355mm access with transparent acrylic cover for easy media loading
• ✅ GRP Construction – Hand-laid glass fibre reinforced polyester ensures absolute watertightness and corrosion resistance
• ✅ Steel Reinforcement – Additional steel at high-stress points for exceptional long-term durability
• ✅ AFM® Optimised Diffuser – Special diffuser prevents crater formation for ideal water distribution
• ✅ 3″ Sight Glass – Large sight glass for clear backwash water monitoring
• ✅ Pressure Gauge Included – Factory-fitted gauge for accurate filter condition monitoring
• ✅ Drain Plug & Vent – Complete with all essential fittings for installation and winterisation
• ✅ Besgo Valve Compatible – Works with automatic or manual Besgo backwash valve systems (sold separately)
• ✅ EN 13121-3 Certified – Manufactured to European pressure vessel standards
• ✅ 5-Year Tank Warranty – Comprehensive manufacturer warranty for complete peace of mind

⚙️ Technical Specifications

Specification	Value
Filter Type	Semi-High Bed Sand/AFM Filter
Tank Diameter	960 mm
Filter Area	0.70 m²
Filter Bed Height	900 mm
Flow Rate (Standard @ 30 m³/h/m²)	21 m³/h
Flow Rate (Backwash @ 50 m³/h/m²)	35 m³/h
Pool Capacity (6-hour turnover)	Up to 126,000 litres
Pool Capacity (8-hour turnover)	Up to 168,000 litres
Inlet/Outlet Connections	2½” Female Thread (F”)
Tank Height	1520 mm
Distance from Ground	405 mm
Connection Spacing	250 mm
Filter Opening at Top	ø 205 mm
Manhole Diameter	ø 355 mm
Sight Glass Size	3″
Maximum Operating Pressure	2.5 bar
Test Pressure	3.75 bar
Maximum Temperature	40°C
Tank Material	GRP (Glass Fibre Reinforced Polyester)
Tank Colour	Blue RAL 5015 (White available on request)
Weight (Empty)	125 kg
Certification	EN 13121-3
Warranty	5 Years (Tank)

📐 Pool Sizing Guide

The AFM/P-960 is engineered for optimal performance with large pools requiring a complete water turnover every 6-8 hours. With an exceptional standard flow rate of 21 m³/h, this flagship filter delivers reliable filtration for commercial pools and large-scale installations.

Sizing Formula:

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

Pool Size Compatibility:

Pool Type	Volume Range	Suitability
🏊 Extra large in-ground	100,000-126,000 L	✅ Excellent – optimal 6-hour turnover
🏢 Medium commercial	100,000-126,000 L	✅ Ideal – professional 6-hour turnover
🏢 Large commercial	126,000-168,000 L	✅ Good – reliable 8-hour turnover
🏨 Hotel main pools	Up to 150,000 L	✅ Professional performance
🏫 School/college pools	Up to 126,000 L	✅ Excellent institutional choice
🏢 Leisure centre pools	Up to 168,000 L	✅ Commercial-grade reliability
🏊 Competition pools	Up to 126,000 L	✅ High-performance filtration
🏊 Very large pools	170,000+ L	⚠️ Consider multiple filters or industrial solution

This Filter:

📍 Standard Flow Rate: 21 m³/h
📍 Backwash Flow Rate: 35 m³/h  
📍 Optimal for pools up to: 126,000 litres (6-hour turnover)
📍 Maximum for pools up to: 168,000 litres (8-hour turnover)

🔌 Installation Requirements

Plumbing Connections:

Requirement	Specification
Inlet Connection	2½” Female Thread (F”)
Outlet Connection	2½” Female Thread (F”)
Valve Position	Side Mount
Connection Spacing	250 mm centre-to-centre

⚠️ Note: The AFM/P-960 features larger 2½” connections (compared to 2″ on smaller models) for improved flow characteristics and reduced pressure loss at higher flow rates.

Physical Installation:

Requirement	Details
Base	Solid, level reinforced concrete pad required
Total Height	1520 mm
Distance from Ground to Connections	405 mm
Clearance Above	Minimum 700 mm for lid removal and media access
Clearance Around	Minimum 900 mm for maintenance access
Weight Consideration	125 kg empty – professional installation recommended

Pump Compatibility:

⚠️ Filter must be matched with an appropriate commercial-grade pump.
✅ Recommended pump flow rate: 16 - 21 m³/h (standard filtration)
✅ Backwash capable pump: Up to 35 m³/h
❌ Pump must not exceed filter's maximum flow rate of 35 m³/h
💡 Consider variable speed pumps for energy efficiency in commercial settings

Valve Requirements:

The AFM/P-960 is designed for use with the Besgo automatic backwash valve system (available in automatic or manual versions). A coupling set is required and sold separately. For this flagship model, the larger Besgo valve sizes are recommended to match the 2½” connections.

🛠️ Maintenance Guide

Routine Maintenance Schedule:

Task	Frequency	Method
Check pressure gauge	Daily (commercial) / Weekly (residential)	Normal operating range: 0.8-1.5 bar
Backwash filter	When pressure rises 0.5-1 bar above clean baseline	Run until sight glass shows clear water
Rinse after backwash	After each backwash	30-60 seconds to settle media
Inspect seals and gaskets	Monthly (commercial) / Seasonally (residential)	Replace if worn or cracked
Check media level	Quarterly (commercial) / Annually (residential)	Top up if below recommended level
Full media replacement	Every 5-7 years (sand) or 10+ years (AFM®)	Replace completely

Pressure Gauge Guide:

📊 Clean filter baseline: 0.8 - 1.0 bar (typical)
📊 Backwash required: When pressure rises 0.5 - 1.0 bar above baseline
📊 Maximum operating pressure: 2.5 bar
⚠️ If pressure exceeds 2.5 bar, stop pump immediately and investigate

Commercial Pool Considerations:

For commercial installations with high bather loads:

• Monitor pressure gauge more frequently during peak usage periods
• Consider automated backwash scheduling via Besgo control panel
• Maintain detailed maintenance logs for regulatory compliance
• Schedule backwashing during low-usage periods to minimise disruption

Winterisation (UK Climate):

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

• Fully drain the filter tank using the drain plug
• Remove and safely store the drain plug
• Leave all valves in open position to allow any residual water to drain
• Cover the filter or store in a frost-free location if possible
• Never leave water standing in the filter during freezing conditions
• Inspect all seals before recommissioning in spring

🪨 Filter Media Information

Media Capacity Requirements:

Media Type	Quantity Required
Sand/Gravel (25 kg bags)	21 bags coarse + 10 bags medium + 10 bags fine (41 bags total)
AFM® Glass Media (21 kg bags)	22 bags Grade 1 + 11 bags Grade 2 + 11 bags Grade 3 (44 bags total)

Three-Layer Media Configuration:

The AFM/P-960’s substantial capacity requires a properly layered media bed for optimal filtration:

Layer	Sand/Gravel	AFM® Glass Media	Purpose
Bottom (Support)	10 bags coarse gravel	11 bags Grade 3	Supports media, covers laterals
Middle (Transition)	10 bags medium grade	11 bags Grade 2	Transition layer
Top (Filtration)	21 bags fine sand	22 bags Grade 1	Primary filtration layer

Compatible Media Comparison:

Media Type	Filtration Rating	Lifespan	Key Benefits
Silica Sand	20-40 microns	5-7 years	Economical, widely available
AFM® Glass Media	Down to 1 micron*	10-15+ years	Superior clarity, self-sterilising, reduces chlorine demand
ZeoSand	3-5 microns	5 years	Enhanced clarity, ammonia reduction

*With proper flocculation

Why Choose AFM® Activated Filter Media for Commercial Pools:

AFM® (Activated Filter Media) is specifically optimised for this filter and offers significant advantages for commercial installations:

• Filters particles down to 1 micron (compared to 20-40 microns with sand)
• Self-sterilising surface prevents bacterial biofilm growth
• Reduces chlorine consumption by up to 50% – significant cost savings at commercial scale
• Requires 50% less backwash water – reduced water and heating costs
• Maintains consistent performance for 10-15+ years – lower lifetime cost
• Bio-resistant – eliminates trichloramine and chlorine smell for improved air quality
• NSF/ANSI certified for pools and drinking water
• Helps meet stringent commercial pool water quality standards

Signs Your Media Needs Replacing:

• Poor water clarity despite correct chemical balance
• Increasingly short filter cycles between backwashes
• Cloudy water returning to pool after filtration
• Media visible in pool (indicates lateral damage)
• Filter pressure consistently higher than normal even after backwash

🔬 Filtration Performance

Performance Metric	Value
Filter Area	0.70 m²
Filter Bed Height	900 mm
Standard Flow Rate	21 m³/h @ 30 m³/h/m²
Backwash Flow Rate	35 m³/h @ 50 m³/h/m²

Micron Rating Guide:

Rating	What It Removes
40+ microns	Visible debris, leaves, large particles
20-40 microns	Sand, dirt, visible particles (typical sand filtration)
10-20 microns	Fine particles, some algae spores
5-10 microns	Very fine particles, most algae
1-5 microns	Ultra-fine particles, bacteria (achievable with AFM®)

The AFM/P-960’s semi-high bed design with 900mm media depth provides exceptional contact time, enhancing both mechanical filtration and flocculation processes for superior water clarity in demanding commercial applications.

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🔧 Besgo Valve Functions

The Calplas AFM/P-960 is designed for use with the Besgo automatic backwash valve system, offering simplified operation ideal for commercial pool management:

Function	Description
Filter	Normal filtration mode – water flows through media bed
Backwash	Reverse flow cleans media – automated switching available
Rinse	Settles media after backwash (on applicable models)

Besgo Valve Advantages for Commercial Use:

• ✅ Automatic backwash capability with programmable timer control
• ✅ No need to stop pump during valve operation – continuous filtration
• ✅ Fail-safe design returns to filter mode on power failure
• ✅ Operates in under 2 seconds – minimal disruption
• ✅ Silent operation with no pressure hammer
• ✅ Low pressure loss for efficient backwashing at high flow rates
• ✅ Wall or filter-mounted installation options
• ✅ Can be integrated with BMS (Building Management Systems)

💡 Note: The Besgo valve and coupling set are sold separately. For the AFM/P-960, ensure valve sizing matches the 2½” connections. Contact Parts4Tubs for compatible options.

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🎯 Ideal Applications

Application	Pool Size	Suitability
🏢 Commercial swimming pools	100,000-168,000 L	✅ Flagship choice
🏨 Hotel main pools	Up to 150,000 L	✅ Professional performance
🏫 School and college pools	Up to 126,000 L	✅ Institutional reliability
🏢 Leisure centre pools	Up to 168,000 L	✅ High-capacity commercial
🏊 Competition/training pools	Up to 126,000 L	✅ Professional standard
🏡 Large estate pools	100,000-150,000 L	✅ Premium residential
🏨 Holiday resort pools	Up to 140,000 L	✅ High-use durability
🧖 Large hydrotherapy facilities	Up to 100,000 L	✅ Excellent with AFM® media

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❓ Frequently Asked Questions

Q: What size pool will this filter handle? A: The AFM/P-960 is suitable for pools up to 168,000 litres with an 8-hour turnover time. For optimal 6-hour turnover (recommended for commercial pools), it’s ideal for pools up to 126,000 litres with its 21 m³/h flow rate.

Q: Why does this model have larger connections? A: The AFM/P-960 features 2½” connections (compared to 2″ on smaller models) to accommodate the higher flow rates and reduce pressure loss across the system. This improves overall hydraulic efficiency, particularly important in commercial installations.

Q: How often do I need to backwash in a commercial setting? A: Commercial pools typically require more frequent backwashing due to higher bather loads. Monitor the pressure gauge daily and backwash when it reads 0.5-1 bar above the clean baseline. Many commercial operators schedule automatic backwashing during quiet periods using the Besgo control system.

Q: What filter media should I use? A: The filter is compatible with silica sand or AFM® glass media. For commercial applications, we strongly recommend AFM® Activated Filter Media which provides filtration down to 1 micron, reduces chlorine consumption by up to 50%, and lasts 10+ years. This model requires a three-layer media configuration: Sand capacity is approximately 1,025 kg (21+10+10 bags of 25kg). AFM® capacity is 44 bags of 21 kg (22 bags Grade 1 + 11 bags Grade 2 + 11 bags Grade 3).

Q: What pump do I need? A: Match with a commercial-grade pump delivering 16-21 m³/h for standard filtration. Ensure the pump can provide up to 35 m³/h for effective backwashing. Variable speed pumps are recommended for commercial installations to optimise energy efficiency.

Q: Is this the largest filter in the range? A: Yes, the AFM/P-960 is the flagship model in the Calplas AFM/P range, offering maximum capacity with 0.70 m² filter area. For pools exceeding 168,000 litres, consider using multiple filters in parallel or contact Parts4Tubs for industrial filtration solutions.

Q: How does this compare to smaller models? A: The AFM/P-960 offers 0.70 m² filter area – 3.5 times the 520 model (0.20 m²), more than double the 640 (0.30 m²), 75% more than the 720 (0.40 m²), and 35% more than the 840 (0.52 m²). It also features larger 2½” connections and a bigger 355mm manhole.

Q: What warranty is included? A: The Calplas AFM/P-960 comes with a 5-year tank warranty. Contact Parts4Tubs for full warranty terms and conditions.

Q: Can this be integrated with pool management systems? A: Yes, when used with the Besgo automatic backwash valve and control panel, the system can be integrated with Building Management Systems (BMS) for centralised monitoring and automated scheduling.

📥 Downloads & Resources

📄 Calplas AFM/P Series Technical Datasheet – Complete specifications for all AFM/P models

🏆 Why Choose the Calplas AFM/P-960

• ✅ Flagship Capacity – 0.70 m² filter area handles pools up to 168,000 litres
• ✅ Commercial Grade – Designed for hotels, leisure centres, schools, and professional pools
• ✅ Enhanced Connections – Larger 2½” connections for improved flow and reduced pressure loss
• ✅ Extra-Large Manhole – 355mm access for easy media loading and maintenance
• ✅ Premium Spanish Engineering – Over 50 years of filter manufacturing expertise from Calplas
• ✅ Superior Build Quality – Hand-laid GRP construction with steel reinforcement
• ✅ Outstanding Filtration – 900mm semi-high bed provides extended contact time for crystal clear water
• ✅ AFM® Optimised – Special diffuser designed specifically for activated glass media performance
• ✅ Future-Proof Design – Compatible with Besgo automatic backwash and BMS integration
• ✅ Proven Reliability – EN 13121-3 certified with 5-year tank warranty

🤝 Why Buy from Parts4Tubs

• ✅ UK-based company with local customer support
• ✅ Fast UK delivery on all orders
• ✅ Expert advice from pool and spa specialists
• ✅ Competitive pricing on all Calplas products
• ✅ Commercial project support and bulk pricing available
• ✅ Full warranty support and after-sales service
• ✅ Easy returns within 30 days
• ✅ Compatible filter media, pumps, and spare parts available
• ✅ Besgo valves and coupling sets in stock

✨ Summary

The Calplas AFM/P-960 Side Mount Filter is the flagship model in the range, delivering exceptional commercial-grade filtration for large pools up to 168,000 litres. With its impressive 960mm GRP tank and 0.70 m² filter area, this Spanish-engineered filter provides 3.5 times the capacity of the entry-level 520mm model. Enhanced features include larger 2½” connections for improved hydraulic efficiency, an extra-large 355mm service manhole, and compatibility with Besgo automatic backwash systems for hands-free commercial operation. The 900mm semi-high bed design ensures outstanding water clarity when paired with AFM® activated glass media. Backed by a 5-year tank warranty and EN 13121-3 certification, the AFM/P-960 is the definitive choice for hotels, leisure centres, schools, and demanding pool installations requiring powerful, reliable filtration.

Order your Calplas AFM/P-960 today – the ultimate solution for large pool filtration!