💦 Lacron Finaflow FF42416 42″ Sand Filter Tank – 43m³/h Flow Rate

Commercial-grade deep bed filtration for large pools, leisure facilities, and demanding installations

🏊 Product Overview

The Lacron Finaflow FF42416 is the flagship model in Lacron’s acclaimed Finaflow range, delivering commercial-grade filtration performance for the largest residential pools, leisure facilities, and light commercial installations. With an exceptional 43m³/h flow rate and massive 1100mm (42″) diameter tank, this filter handles pools up to 344,000 litres with the superior water clarity that only deep bed technology can provide.

As the largest standard Finaflow model, the FF42416 represents the ultimate in domestic and light commercial deep bed filtration. The signature Finaflow design provides a minimum 1-metre media depth, ensuring water remains in contact with filter media significantly longer than conventional high-rate filters. This extended contact time captures finer particles, colloidal substances, and delivers the exceptional water clarity demanded by professional installations and discerning pool owners.

Manufactured from extremely hard-wearing glass reinforced polyester (GRP), the FF42416 features Lacron’s smooth high-gloss internal and external finish that ensures free water flow and simplified cleaning. All internal components and pipework are upgraded to the highest commercial standard, delivering the reliability and longevity essential for high-capacity installations. The substantial tank size accommodates a very large media bed, providing exceptional dirt-holding capacity and extended intervals between backwash cycles. Supplied as a tank-only unit with service hatch and sight glass, the FF42416 offers flexibility to specify your preferred valve configuration. Backed by Lacron’s 35+ year proven track record, this filter represents the professional choice for serious filtration requirements.

⭐ Key Features

✅ Maximum Flow Capacity – Exceptional 43m³/h flow rate for pools up to 344,000 litres

✅ 1100mm (42″) Commercial-Grade Tank – Massive filtration area for demanding applications

✅ Deep Media Bed Technology – Minimum 1-metre filtration bed depth for superior particle capture

✅ Glass Reinforced Polyester Construction – Extremely hard-wearing GRP tank with smooth high-gloss finish

✅ Commercial-Standard Internals – All pipework and components upgraded to highest commercial grade

✅ Hydraulically Balanced Laterals – Optimised water distribution maximises filtration efficiency

✅ Clear Inspection Lid – Easy visual monitoring of media condition during operation

✅ Media Sight Glass – Observe filter bed and backwash progress without system shutdown

✅ Media Service Hatch – Rapid access for efficient media removal and changes

✅ Inflow Diffuser – Evenly distributes water flow across the entire filter bed surface

✅ Pressure Tested to 4 Bar – Rigorous factory testing ensures reliable commercial performance

✅ UV & Corrosion Resistant – Built to withstand harsh pool environments and outdoor installation

🔧 Technical Specifications

Specification	Value
Model	FF42416
Filter Type	Deep Bed Sand Filter (Tank Only)
Tank Diameter	42″ (1100mm)
Flow Rate	43.0m³/h
Minimum Bed Depth	1 metre
Filtration Rating	20-40 microns (with sand media)
Test Pressure	4 bar
Maximum Working Pressure	2.5 bar
Tank Material	Glass Reinforced Polyester (GRP)
Internal Finish	Smooth high-gloss
Lateral System	Hydraulically balanced
Valve Included	No – Tank Only
Air Vent	Manual
Water Drain	Manual
Inspection Lid	Clear
Media Sight Glass	Yes
Service Hatch	Yes
Filter Base	Included for stable floor mounting
Manufacturer	Lacron (Waterco Group)

💡 Note: For connection size and valve specifications, please contact Parts4Tubs to confirm compatibility with your installation requirements.

📏 Pool Sizing Guide

The Lacron Finaflow FF42416 delivers exceptional filtration for the largest residential pools, holiday complexes, and light commercial applications. Pool filtration systems should turn over the entire pool volume within 6-8 hours for optimal water quality.

Sizing Calculation:

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

Pool Size Compatibility:

Pool Type	Volume Range	Suitability
🏠 Very Large Residential	150,000-250,000 L	✅ Excellent – optimal performance
🏠 Estate/Mansion Pools	250,000-344,000 L	✅ Very Good – 8-hour turnover
🏨 Holiday Complex Pools	Up to 260,000 L	✅ Excellent – reduced maintenance
🏢 Light Commercial	Up to 260,000 L	✅ Good – verify PWTAG compliance
🧖 Large Commercial Swim Spas	50,000-100,000 L	✅ Premium – rapid turnover
🏫 Small School/Club Pools	Verify requirements	⚠️ Consult regulations

This Filter:

📍 Flow Rate: 43.0m³/h
📍 Optimal Pool Size: Up to 258,000 litres (6-hour turnover)
📍 Maximum Pool Size: Up to 344,000 litres (8-hour turnover)

💡 Tip: The FF42416 delivers over 3× the flow capacity of the FF24416 (43.0 vs 13.5m³/h) and over 2× the FF30416 (43.0 vs 20.0m³/h). For pools exceeding 200,000 litres, this is the definitive Finaflow choice.

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🛠️ Installation Requirements

Important: This is a tank only product. A multiport valve must be purchased separately.

Plumbing Connections:

Requirement	Specification
Valve Type Required	Large-bore side-mount multiport (purchased separately)
Connection Size	Contact Parts4Tubs for confirmation
Pipework	Large-bore pipework recommended throughout

Physical Installation:

Requirement	Details
Base	Heavy-duty reinforced concrete pad essential – substantial weight when filled
Clearance Above	Minimum 800mm for lid removal and maintenance
Clearance Around	Minimum 700mm for service hatch and valve access
Location	Protect from direct sunlight where possible
Access	Consider delivery and positioning logistics for large tank
Structural	Verify floor loading capacity for filled weight

Pump Compatibility:

⚠️ Important: The FF42416 requires a suitably powerful pump system to achieve optimal performance.

Parameter	Recommendation
Recommended Pump Flow	30.0 – 43.0m³/h
Maximum Pump Flow	Do not exceed 43.0m³/h
System Pressure	Must not exceed 2.5 bar during operation
Pump Configuration	Single large pump or multiple pump system

💡 Professional Installation Recommended: Due to the size and capacity of the FF42416, professional installation by a qualified pool engineer is strongly recommended.

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🔄 Maintenance Guide

Routine Maintenance Schedule:

Task	Frequency	Method
Check pressure gauge	Weekly	Note baseline reading when clean
Visual bed inspection	Weekly	Check through sight glass during operation
Backwash filter	When pressure rises 0.5-0.7 bar	Run until sight glass shows clear water
Rinse after backwash	After every backwash	90-120 seconds to settle large media bed
Inspect valve seals	Seasonally	Replace if worn or leaking
Check media level	Annually	Top up if low via service hatch
Full media replacement	Every 5-7 years (sand)	Access via service hatch

Pressure Gauge Guide:

📊 Clean filter baseline: 0.8-1.2 bar (typical)
📊 Backwash recommended: 0.5-0.7 bar above baseline
📊 Maximum operating: 2.5 bar

Deep Bed Advantage: The 1-metre minimum bed depth combined with the 42″ tank diameter provides exceptional dirt-holding capacity. The FF42416 typically requires less frequent backwashing than smaller filters, even on high-load installations.

⚠️ Backwash Considerations: The large media bed requires significant water volume for effective backwashing. Ensure adequate drainage capacity and water supply for backwash operations.

Winterisation (Essential for UK Climate):

1. Switch off pump and allow system to depressurise
2. Drain filter tank completely via manual drain – allow extended time for large media volume
3. Open air vent to assist complete drainage
4. Remove and store drain plug safely
5. Leave valve (if fitted) in intermediate position
6. Cover filter or protect from frost

⚠️ Critical: The 42″ tank with deep media bed retains very substantial water volume. Allow adequate time (potentially several hours) for complete drainage before freezing conditions to prevent catastrophic tank damage.

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🪨 Filter Media Information

The Lacron Finaflow FF42416’s substantial tank size and deep bed design require significant media quantities to achieve optimum performance.

Recommended Media Types:

Media Type	Size	Filtration Rating	Benefits
Lacronite (Zeolite)	As supplied	3-5 microns	Superior clarity, reduced chemicals, longer life
Filter Sand	0.5-1.4mm (16/30 grade)	20-40 microns	Economical, proven performance
Glass Media	0.5-1.0mm	5-15 microns	Finer filtration, eco-friendly

Media Capacity: Contact Parts4Tubs for specific media quantities for the FF42416. The 42″ tank requires substantial media investment.

💡 Media Investment: Given the significant media quantity required for the FF42416, consider glass media or Lacronite for extended service life (10+ years vs 5-7 years for sand), offsetting higher initial cost with reduced long-term replacement frequency.

Lacronite Advantages:

• Superior water clarity
• Remarkable dirt retention properties
• Reduced backwashing frequency
• Lower chemical costs
• Improved bather comfort
• Extended media lifespan

Signs Media Needs Replacing:

• Persistently cloudy water despite correct chemical balance
• Shortened filter cycles requiring frequent backwashing
• Visible media particles in pool returns
• Media channelling visible through sight glass
• Increased chemical consumption without improved clarity

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💎 Filtration Performance

Metric	Value
Filtration Rating (Sand)	20-40 microns
Filtration Rating (Lacronite)	3-5 microns
Design Flow Rate	43.0m³/h
Minimum Bed Depth	1 metre
Deep Bed Advantage	Maximum particle capture and dirt retention

Micron Rating Guide:

Rating	What It Removes
40+ microns	Visible debris, leaves, large particles
20-40 microns	Sand, dirt, visible suspended particles
10-20 microns	Fine particles, some algae spores
5-10 microns	Very fine particles, most algae
3-5 microns	Near-invisible particles, colloidal matter

Deep Bed Filtration Advantage:

The Finaflow’s minimum 1-metre media bed depth delivers:

• Extended Contact Time – Water remains in contact with media longer, capturing finer particles
• Maximum Dirt Retention – Large media volume holds exceptional amounts of dirt before backwashing
• Colloidal Particle Capture – Removes fine suspended matter that passes through shallow beds
• Superior Water Clarity – Noticeably clearer water, especially in high-load situations
• Reduced Chemical Demand – Cleaner water requires fewer treatment chemicals

FF42416 Performance Position:

Model	Size	Flow Rate	Capacity Increase vs FF24416
FF24416	24″ (610mm)	13.5m³/h	Baseline
FF30416	30″ (760mm)	20.0m³/h	+48%
FF42416	42″ (1100mm)	43.0m³/h	+219%

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⚙️ Valve Information

Important: The FF42416 is supplied as a tank only unit. A multiport valve must be purchased separately.

Compatible Valve Options:

Option	Description
ZZ3270NS	42″ Finaflow complete with valve & gauge (if available)
Large-bore Multiport	Contact Parts4Tubs for compatible valve options

Standard 6-Way Valve Functions:

Position	Function	When to Use
Filter	Normal filtration mode	Daily operation
Backwash	Reverses flow to clean media	When pressure rises above baseline
Rinse	Settles media after backwash	90-120 seconds after backwash
Waste	Bypasses filter, drains to waste	Vacuuming heavy debris, lowering water
Recirculate	Bypasses filter, returns to pool	Distributing chemicals
Closed	Stops all water flow	Maintenance, winterisation

💡 Valve Selection: Due to the high flow rate of the FF42416, valve selection is critical. Contact Parts4Tubs to ensure correct valve specification for your installation.

🎯 Ideal Applications

Application	Pool Size	Suitability
🏠 Very Large Residential	150,000-250,000 L	✅ Excellent – ideal match
🏠 Estate/Mansion Pools	250,000-344,000 L	✅ Very Good
🏨 Holiday Complexes	Up to 260,000 L	✅ Excellent
🏢 Boutique Hotels	Up to 260,000 L	✅ Good – verify regulations
🧖 Large Swim Spas/Therapy Pools	50,000-100,000 L	✅ Premium – rapid turnover
♨️ Warmer Water Installations	Various	✅ Specifically designed
🏊 High Bather Load Pools	Various	✅ Specifically designed
🏫 Small Institutional	Verify requirements	⚠️ Consult PWTAG

Particularly Recommended For:

• Very large residential pools requiring commercial-grade filtration
• Estate properties and high-end residential installations
• Holiday rental complexes requiring reliable, low-maintenance filtration
• Pools and spas operating with warmer water temperatures
• Installations with higher bather loads requiring enhanced filtration
• Upgrades from multiple smaller filters to single high-capacity unit
• Pool owners seeking the ultimate in Finaflow filtration performance
• Professional installations requiring commercial-grade reliability

❓ Frequently Asked Questions

Q: What size pool will this filter handle? A: The FF42416 is suitable for pools up to 344,000 litres with an 8-hour turnover, or optimally up to 258,000 litres with a 6-hour turnover. The exceptional 43.0m³/h flow rate makes it suitable for the largest residential and light commercial pools.

Q: Does this filter come with a valve? A: No, the FF42416 is supplied as a tank only unit. You will need to purchase a compatible large-bore multiport valve separately. Contact Parts4Tubs for valve recommendations and availability.

Q: How does this compare to the smaller Finaflow models? A: The FF42416 delivers 219% more flow capacity than the FF24416 (43.0 vs 13.5m³/h) and 115% more than the FF30416 (43.0 vs 20.0m³/h). It’s designed for pools approximately 3× larger than those suited to the FF24416.

Q: How often do I need to backwash? A: Backwash when the pressure gauge reads 0.5-0.7 bar above your clean baseline. The large media bed provides exceptional dirt-holding capacity, often allowing longer intervals between backwashes than smaller filters.

Q: What filter media should I use? A: Lacron recommends either Lacronite (zeolite) for superior 3-5 micron filtration, or 16/30 grade sand (0.5-1.4mm) for standard 20-40 micron filtration. Given the substantial media quantity required, consider long-life media options.

Q: Is professional installation required? A: While not mandatory, professional installation is strongly recommended due to the size, weight, and plumbing requirements of the FF42416. A qualified pool engineer can ensure correct installation and optimal performance.

Q: Is this suitable for commercial use? A: The FF42416 is designed for domestic and light commercial applications. For regulated commercial pools, verify compliance with PWTAG guidelines and local authority requirements.

Q: What pump do I need? A: You’ll need a pump or pump system capable of delivering 30-43m³/h. Never exceed the filter’s maximum flow rate, and ensure system pressure stays within the 2.5 bar maximum. Contact Parts4Tubs for pump recommendations.

Q: What warranty is included? A: Lacron products are backed by manufacturer warranty. Contact Parts4Tubs for full warranty terms and conditions.

🏆 Why Choose the Lacron Finaflow FF42416

✅ Maximum Finaflow Performance – 43.0m³/h flow rate handles pools up to 344,000 litres

✅ Commercial-Grade Construction – GRP tank with highest commercial standard internals

✅ Superior Deep Bed Filtration – 1-metre minimum bed depth captures finer particles than standard filters

✅ Exceptional Dirt Capacity – Large media bed extends intervals between backwashes

✅ Proven Performance – Lacron’s 35+ year track record of reliability

✅ Enhanced Water Clarity – Deep bed technology removes colloidal particles for crystal-clear water

✅ Reduced Maintenance – Greater capacity means less frequent servicing

✅ Easy Servicing – Service hatch and sight glass simplify maintenance

✅ Ideal for Demanding Applications – Specifically designed for warmer water and high bather loads

✅ Lower Running Costs – Reduced chemical demand and backwash frequency

🛒 Why Buy From Parts4Tubs

✅ UK-Based Company – Local support and expertise you can rely on

✅ Fast UK Delivery – Coordinated delivery for large equipment

✅ Expert Advice – Our team can assist with valve selection, media quantities, and installation planning

✅ Competitive Pricing – Great value on genuine Lacron commercial equipment

✅ Full Warranty Support – We stand behind every product we sell

✅ Easy Returns – Hassle-free returns policy

✅ Complete Range – Matching valves, filter media, spare parts, and accessories available

✅ Trusted Supplier – Built on years of industry experience

🌊 Summary

The Lacron Finaflow FF42416 is the flagship model in Lacron’s acclaimed Finaflow range, delivering commercial-grade deep bed filtration for pools up to 344,000 litres. With an exceptional 43m³/h flow rate – over 3× the capacity of the FF24416 – and a massive 1100mm (42″) diameter tank, this filter provides the ultimate in domestic and light commercial filtration performance. The minimum 1-metre media bed depth captures finer particles and colloidal substances for exceptional water clarity, while the substantial media capacity extends backwash intervals and reduces maintenance requirements. Built to the highest commercial standards with GRP construction, service hatch, sight glass, and hydraulically balanced laterals, the FF42416 represents the definitive choice for pool owners and professionals seeking uncompromising filtration performance. Backed by Lacron’s 35+ year industry reputation, this is serious filtration for serious pools.