🌊 Waterco 900 SMDD Commercial Bobbin Wound Filter Tank – 4 Bar, 1.2 Metre Deep Bed

Professional deep bed filtration with upgraded 3-inch connections for medium commercial pools and hotel facilities

💦 Product Overview

The Waterco 900 SMDD Commercial Bobbin Wound Filter Tank delivers the ideal balance of capacity and footprint for medium-sized commercial pools, hotel facilities, fitness centres, and community pools. With a 900mm tank diameter and 0.64 m² filter area, this filter provides a 19 m³/hr flow rate – representing a significant 46% increase over the entry-level SMDD 750 while maintaining a manageable installation footprint.

Featuring upgraded 90mm (3-inch) flange connections – the first step up from 2-inch in the SMDD range – the 900 model delivers enhanced flow capacity essential for medium commercial applications. The generous 1200mm deep media bed provides the same superior in-depth filtration performance found across all SMDD models, ensuring exceptional water clarity and extended filter runs between backwashes.

Built using Waterco’s precision digitally-controlled filament winding technology, this commercial filter tank features seamless bobbin-wound fibreglass construction engineered for decades of reliable service in demanding aquatic environments. The tank-only configuration with 4 bar pressure rating offers complete flexibility for system design and component selection.

💫 Key Features

✅ 900mm Tank Diameter – Optimal balance of capacity and footprint for medium commercial applications

✅ 0.64 m² Filter Area – 46% larger than SMDD 750, handling pools up to 152,000 litres

✅ 90mm / 3″ Flange Connections – Upgraded flow capacity for commercial pump systems

✅ 1200mm Deep Media Bed – Superior in-depth filtration matching larger SMDD models

✅ 1,200 kg Sand Capacity – Substantial media volume for excellent dirt-holding and extended runs

✅ Advanced Bobbin Wound Construction – Seamless fibreglass vessel with exceptional structural integrity

✅ 4 Bar Pressure Rating – Engineered for demanding commercial system pressures

✅ Fishtail Lateral System – Waterco’s patented design eliminates dead spots and maximises hydraulic efficiency

✅ Double Yoke Lid with Lifting Eye – Safe handling during installation and maintenance

✅ Service Hatch & 8-Bolt Flanges – Standard equipment for easy access and secure connections

✅ Large Clear Sight Glass – Visual backwash monitoring for optimal media cleaning

✅ Corrosion & UV Resistant – Premium fibreglass withstands chemicals and outdoor exposure

⚙️ Technical Specifications

Specification	Value
Model	SMDD 900
Filter Type	Commercial Sand/Media Filter (Tank Only)
Tank Diameter	900 mm
Filter Bed Depth	1200 mm
Filter Area	0.64 m²
Flow Rate	19 m³/hr (at 30 m³/hr/m²)
Working Pressure	4 Bar (58 psi)
Maximum Working Temperature	50°C
Connection Size	3″ / 90 mm (Flange)
Sand Media Capacity	1,200 kg
Glass Media Capacity	986 kg
Gravel Capacity	180 kg (if using support layer)
Tank Height (Overall)	2268 mm
Tank Width	923 mm
Empty Weight	177 kg
Tank Material	Fibreglass Reinforced Polyester (Bobbin Wound)
Lateral System	Fishtail Configuration
Warranty	10 years tank (5 years full + 5 years pro rata), 1 year components

📐 Pool Sizing Guide

Sizing Principle:

The filter’s flow rate should achieve complete pool water turnover within the required timeframe. Commercial pools typically require 6-hour turnover rates, with 8-hour turnover as the maximum acceptable for lower-demand applications.

Formula:

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

Pool Capacity Compatibility:

Application	Turnover Time	Maximum Pool Volume
🏨 Hotel/Resort Pool	6 hours	114,000 litres
🏋️ Fitness Centre Pool	6 hours	114,000 litres
🏫 School/College Pool	6 hours	114,000 litres
🏢 Community Centre Pool	6-8 hours	114,000-152,000 litres
🏠 Large Residential Pool	8 hours	152,000 litres

This Filter:

📍 Flow Rate: 19 m³/hr at design velocity
📍 Optimal Pool Size: Up to 114,000 litres (6-hour turnover)
📍 Maximum Pool Size: Up to 152,000 litres (8-hour turnover)

💡 Sizing Guidance: The SMDD 900 offers 46% more capacity than the SMDD 750. For larger pools requiring higher flow rates, consider the SMDD 1050 (26 m³/hr) or SMDD 1200 (34 m³/hr), both of which share the same 3-inch connections.

🛠️ Installation Requirements

Plumbing Specifications

Requirement	Specification
Inlet Connection	90 mm / 3″ Flange
Outlet Connection	90 mm / 3″ Flange
Connection Type	8-Bolt Flange
Filter Configuration	Side Mount

Physical Installation

Requirement	Details
Base	Solid, level concrete pad required
Clearance Above	Minimum 500 mm for lid removal and media access
Clearance Around	Minimum 600 mm for valve operation and maintenance
Access	Service hatch for media inspection and replacement
Lifting Equipment	Required – 177 kg empty weight
Floor Loading	Verify capacity (filled weight approximately 1,400 kg)

Pump Compatibility

⚠️ Important: Filter must be matched with appropriate pump rated for 3″ pipework.

• Recommended Pump Flow Rate: 15 – 19 m³/hr
• Maximum Flow Rate: Do not exceed 19 m³/hr to prevent media migration
• Minimum Flow Rate: Ensure adequate velocity for proper filtration
• Connection: 90mm / 3″ to match filter flanges

💡 Note: This is a tank-only product. Multiport valves, face pipework kits, and pumps are sold separately. Contact Parts4Tubs for compatible 3″ valve and pipework options.

🔄 Maintenance Guide

Routine Maintenance Schedule

Task	Frequency	Procedure
Check pressure gauge	Weekly	Record baseline and monitor for increases
Visual inspection	Weekly	Check for leaks, unusual sounds, pressure anomalies
Backwash	When pressure rises 0.5-0.7 bar above clean baseline	Until sight glass runs clear
Rinse after backwash	After each backwash	Run for 30-60 seconds to settle media
Inspect sight glass	Monthly	Clean if visibility reduced
Check O-rings and seals	Quarterly	Replace if worn or damaged
Inspect media level	Annually	Top up if below recommended level
Full media replacement	Every 5-7 years (sand) or 10+ years (glass)	Replace completely

Pressure Gauge Guide

📊 Clean Filter Baseline: Establish after fresh media installation
📊 Backwash Trigger: 0.5-0.7 bar above baseline
📊 Maximum Operating Pressure: 4 bar

⚠️ Warning: Never operate above rated pressure. If pressure remains high after backwashing, inspect for blockages or media issues.

Backwash Considerations

The 1,200 kg media capacity requires appropriate backwash water management:

• Ensure adequate drainage capacity for commercial backwash volumes
• Sufficient water supply for complete rinse cycle
• Compliance with local discharge regulations
• Consider backwash water treatment or recycling for commercial installations

Winterisation (UK Climate)

For outdoor installations or extended shutdown periods:

1. Isolate pump and close all valves
2. Set multiport valve to “Waste” position
3. Open manual drain and allow tank to empty completely
4. Remove drain plug and store safely
5. Open all connections to prevent trapped water
6. Cover or protect from direct weather exposure
7. Never leave water in filter during freezing conditions

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💧 Filter Media Information

Compatible Media Types

Media Type	Filtration Rating	Capacity Required	Lifespan	Key Benefits
Silica Sand	20-40 microns	1,200 kg	5-7 years	Economical, widely available, proven performance
Glass Media	5-15 microns	986 kg	10+ years	Finer filtration, reduced backwash frequency, longer life
ZeoSand/Zeolite	3-5 microns	As specified	5 years	Superior clarity, ammonia removal properties
AFM (Activated Filter Media)	1-5 microns	As specified	10+ years	Bio-resistant, self-sterilising, exceptional clarity

Standard Media Configuration:

• Sand Capacity: 1,200 kg (16/30 grade silica sand)
• Glass Media Capacity: 986 kg
• Support Gravel: 180 kg (deduct from sand capacity if used)

💡 Commercial Recommendation: Glass media provides finer filtration (5-15 microns vs 20-40 microns for sand) and significantly longer service life, making it particularly cost-effective for commercial installations where water quality expectations are high.

Signs Media Needs Replacing

• Persistent poor water clarity despite correct chemical balance
• Shortened filter cycles between backwashes
• Media visible in pool return water
• Channelling or uneven flow distribution
• Excessive pressure drop or abnormally low resistance

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💎 Filtration Performance

Metric	Value
Filter Area	0.64 m²
Design Flow Rate	19 m³/hr
Design Velocity	30 m³/hr/m²
Bed Depth	1200 mm (deep bed design)

Filtration Rating by Media Type

Media	Filtration Rating	What It Captures
Sand (standard)	20-40 microns	Visible debris, leaves, hair, large particles
Glass media	5-15 microns	Fine particles, most algae, improved clarity
AFM/Zeolite	1-5 microns	Very fine particles, colloidal matter, exceptional clarity

Deep Bed Advantage

The 1200mm media bed depth provides significant advantages over standard high-rate filters:

• Enhanced Particle Capture: Deep bed allows progressive filtration throughout the media depth, capturing finer particles that shallow beds miss
• Increased Dirt Capacity: Greater media volume means longer filter runs between backwashes
• Reduced Operating Costs: Less frequent backwashing conserves water and chemicals
• Multi-Media Capability: Deep bed supports layered media configurations for staged filtration
• Commercial Reliability: Consistent performance under variable bather loads

🔧 Valve Positions & Functions

Note: Multiport valve sold separately – 3″ rated valve required

Position	Function
Filter	Normal filtration mode – water flows through media bed
Backwash	Reverse flow to clean media – directs debris to waste
Rinse	Settles media after backwash – brief forward flow to waste
Waste	Bypass filter – pump directly to drain (lowering water level)
Recirculate	Bypass filter – return to pool without filtration
Closed	Stop all flow – isolate filter from system

🏊 Ideal Applications

Application	Suitability	Notes
🏨 Hotel & Resort Pools	✅ Excellent	Ideal capacity for boutique to mid-sized hotel pools
🏋️ Fitness Centre Pools	✅ Excellent	Handles variable bather loads with deep bed technology
🏫 School & College Pools	✅ Excellent	Reliable performance for educational facilities
🏢 Community Centre Pools	✅ Excellent	Cost-effective solution for municipal applications
🏠 Large Residential Pools	✅ Very Good	Commercial-grade upgrade for demanding residential installations
🧖 Spa & Hydrotherapy Pools	✅ Very Good	Superior clarity for therapeutic applications

💬 Frequently Asked Questions

Q: What size pool will this filter handle?

A: The SMDD 900 is suitable for pools up to 114,000 litres with a 6-hour turnover, or up to 152,000 litres with an 8-hour turnover.

Q: How does the SMDD 900 compare to the SMDD 750?

A: The SMDD 900 offers 46% more filter area (0.64 m² vs 0.44 m²) and flow rate (19 m³/hr vs 13 m³/hr). It also upgrades to 3-inch connections from 2-inch, providing enhanced flow capacity for commercial systems.

Q: What pump connections do I need?

A: The SMDD 900 uses 90mm / 3-inch flange connections. You’ll need a compatible 3-inch multiport valve and pipework – the same size used on the SMDD 1050 and 1200.

Q: How much media does this filter require?

A: The filter requires 1,200 kg of sand or 986 kg of glass media. The substantial media capacity provides excellent dirt-holding capability for commercial applications.

Q: How often do I need to backwash?

A: Backwash when the pressure gauge reads 0.5-0.7 bar above the clean filter baseline. Frequency depends on bather load but typically every 1-2 weeks for commercial pools.

Q: Is this a complete filter system?

A: No, this is a tank-only product. You will need to purchase a 3-inch rated multiport valve, face pipework kit, and compatible pump separately. Contact Parts4Tubs for complete system specifications.

Q: What warranty is included?

A: Waterco provides a 10-year tank warranty (5 years full cover plus 5 years pro rata) and 1-year warranty on all other components.

Q: Can this filter be used for saltwater pools?

A: Yes, the fibreglass construction is fully resistant to saltwater and chlorinated environments.

Q: What’s the weight when filled with media?

A: Empty weight is 177 kg. With 1,200 kg of sand media, total filled weight is approximately 1,400 kg. Ensure your plant room floor can support this load.

📄 Downloads & Resources

📄 SMDD Technical Datasheet – Full specifications and dimensions for all SMDD models

✅ Why Choose the Waterco 900 SMDD

✅ Optimal Mid-Range Capacity – 46% more capacity than SMDD 750 in a manageable footprint

✅ Upgraded 3″ Connections – Enhanced flow capacity for commercial pump systems

✅ Same Deep Bed Technology – 1200mm media depth as the largest SMDD models

✅ Substantial Media Capacity – 1,200 kg sand provides excellent dirt-holding

✅ Commercial-Grade Construction – Bobbin wound fibreglass for decades of service

✅ Proven Fishtail Lateral System – Waterco’s patented design for maximum efficiency

✅ Excellent Value – Professional performance at competitive pricing

✅ Comprehensive Warranty – 10-year tank warranty provides peace of mind

🛒 Why Buy from Parts4Tubs

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

✅ Fast UK Delivery – Efficient dispatch on commercial equipment orders

✅ Expert Technical Advice – Get sizing recommendations and system design guidance

✅ Competitive Pricing – Commercial-grade equipment at excellent value

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

✅ Compatible Parts Available – 3″ multiport valves, pipework kits, and media in stock

✅ Easy Returns – 30-day returns on eligible products

🌟 Summary

The Waterco 900 SMDD Commercial Bobbin Wound Filter Tank delivers the perfect balance of capacity and footprint for medium-sized commercial pools, hotel facilities, and fitness centres handling pools up to 114,000 litres (6-hour turnover). With upgraded 90mm (3-inch) flange connections, 0.64 m² filter area, and 19 m³/hr flow rate, this filter offers 46% more capacity than the entry-level SMDD 750 while sharing the same 1200mm deep media bed technology as the largest models in the range. The substantial 1,200 kg sand capacity ensures excellent dirt-holding and extended filter runs. Advanced bobbin-wound fibreglass construction and Waterco’s patented fishtail lateral system deliver decades of reliable commercial service. Supplied as tank only with 4 bar pressure rating. Backed by Waterco’s comprehensive 10-year tank warranty.