🌊 FBT400 Brasil Top Mount Sand Filter – 400mm (15″) 6m³/hr – Up to 18,000 Litre Pool Capacity

Reliable sand filtration for smaller residential pools, delivering crystal clear water with minimal maintenance.

💧 Product Overview

The Certikin FBT400 Brasil Top Mount Sand Filter is a compact yet powerful filtration solution designed specifically for smaller residential and above-ground swimming pools. Manufactured using advanced blow-moulding technology from durable anthracite grey HDPE (High-Density Polyethylene), this filter delivers exceptional performance and longevity for pools up to 18,000 litres.

Featuring a convenient top-mounted 6-way multiport valve, the Brasil filter provides complete control over all filtration operations from a single, easy-to-reach position. The included pressure gauge allows precise monitoring of filter performance, ensuring you always know when backwashing is required for optimal water clarity.

With its robust construction and chemical-resistant materials, the FBT400 is built to withstand the demands of outdoor installation and years of reliable service in the UK climate.

✨ Key Features

✅ 400mm (15″) Filter Diameter – Compact design ideal for smaller pools and tight plant rooms

✅ 6 m³/hr Flow Rate – Efficient water circulation for pools up to 18,000 litres

✅ Blow-Moulded HDPE Construction – Lightweight yet incredibly durable with excellent chemical resistance

✅ 6-Way Multiport Valve – Complete filtration control including filter, backwash, rinse, waste, recirculate, and closed positions

✅ Top Mount Configuration – Easy access for maintenance and space-saving installation

✅ Integrated Pressure Gauge – Monitor filter performance at a glance to optimise backwash timing

✅ Drain Valve Included – Simplifies winterisation and maintenance procedures

✅ 1.5″ (38mm) Connections – Standard sizing for easy integration with existing pool plumbing

✅ UV and Chemical Resistant – Anthracite grey finish protects against sun damage and pool chemicals

✅ CE Certified – Meets European safety and performance standards

⚙️ Technical Specifications

Specification	Value
Model	FBT400
Filter Type	Sand Filter
Tank Diameter	400mm (15″)
Flow Rate	6 m³/hr
Pool Capacity	Up to 18,000 litres
Filter Area	0.125 m²
Sand/Media Capacity	35 kg
Maximum Working Pressure	2 bar (2 kg/cm²)
Inlet/Outlet Size	1.5″ (38mm)
Valve Type	6-Way Top Mount Multiport
Tank Material	HDPE (High-Density Polyethylene)
Manufacturing Method	Blow Moulded
Colour	Anthracite Grey
Included Components	6-Way Valve, Pressure Gauge, Drain Valve

📐 Pool Sizing Guide

Proper filter sizing ensures efficient water circulation and optimal filtration performance. The general principle is that your filter system should turn over the entire pool volume within 6-8 hours.

Sizing Formula:

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

FBT400 Pool Compatibility:

Pool Type	Volume Range	Suitability
🏠 Small above-ground	Up to 10,000 L	✅ Excellent – ideal match
🏠 Medium above-ground	10,000-18,000 L	✅ Good – at designed capacity
🏊 Small in-ground	Up to 18,000 L	✅ Good – suitable for smaller pools
🏊 Medium in-ground	18,000-25,000 L	⚠️ Consider larger filter

This Filter:

📍 Flow Rate: 6 m³/hr (6,000 litres per hour)

📍 Optimal Pool Size: Up to 18,000 litres (approximately 4,000 gallons)

📍 Turnover Time: 3 hours for 18,000L pool (excellent)

💡 Tip: For the best filtration results, aim for a turnover time of 6-8 hours during normal use, running the pump for 8-12 hours daily during peak swimming season.

🔌 Installation Requirements

Plumbing Connections

Requirement	Specification
Inlet Connection	1.5″ (38mm)
Outlet Connection	1.5″ (38mm)
Valve Position	Top Mount
Connection Type	Threaded

Physical Installation

Requirement	Details
Base	Solid, level surface required
Recommended Position	0.5m below pool water level
Clearance Above	Minimum 500mm for valve operation
Clearance Around	Minimum 300mm for maintenance access
Location	Near pool with drain access

Pump Compatibility

⚠️ Important: The filter must be correctly matched with an appropriate pump for optimal performance.

Parameter	Specification
Recommended Pump Flow Rate	4-6 m³/hr
Maximum Pump Flow Rate	6 m³/hr

⚠️ Never exceed the filter’s maximum flow rate. An oversized pump can damage the filter and push debris through the sand bed, reducing filtration effectiveness.

💡 Installation Tip: Use plastic fittings and PTFE tape for all connections. Do not use iron pipes or hemp packing as these can cause contamination and corrosion.

🔄 Maintenance Guide

Routine Maintenance Schedule

Task	Frequency	Method
Check pressure gauge	Weekly	Note baseline reading when clean
Backwash filter	When pressure rises 0.5 bar above baseline	Run until sight glass clears (approx. 2-4 minutes)
Rinse after backwash	After every backwash	Run for 30-60 seconds
Inspect O-rings and seals	Monthly during season	Replace if worn or cracked
Check sand level	Annually	Top up if visibly low
Clean sand with filter cleaner	Annually	Use Certikin Filnet or similar product
Full sand replacement	Every 3 years	Replace entire sand charge

Pressure Gauge Guide

📊 Clean filter baseline: 0.8 bar (11.4 PSI)

📊 Backwash required: 1.3 bar (18.5 PSI) – 0.5 bar above baseline

📊 Maximum operating: 2.0 bar (29 PSI)

⚠️ Warning: Never operate the filter if pressure exceeds 2.0 bar. Stop the pump immediately and investigate the cause.

Winterisation Procedure (UK Climate)

Proper winterisation is essential to protect your filter during freezing conditions:

1. Perform a full backwash and rinse cycle
2. Turn off pump and close all valves
3. Remove drain plug and allow filter to drain completely
4. Leave drain plug removed to prevent water accumulation
5. Remove filter lid to allow air circulation
6. Cover or relocate to frost-free location if possible

⚠️ Critical: Never leave water in the filter during freezing temperatures. Ice expansion can crack the tank and damage internal components.

🪨 Filter Media Information

Compatible Media Types

Media Type	Filtration Rating	Lifespan	Benefits
Silica Sand (0.5-0.7mm)	20-40 microns	3-5 years	Economical, proven performance
Glass Media	5-15 microns	8-10+ years	Finer filtration, longer life, eco-friendly
ZeoSand/Zeolite	3-5 microns	5 years	Superior water clarity, ammonia absorption

Media Capacity: 35 kg

💡 Recommendation: While standard silica sand provides excellent filtration, consider upgrading to glass media for enhanced water clarity and reduced backwash frequency. Glass media captures finer particles and typically lasts twice as long as traditional sand.

Signs Your Media Needs Replacing

• Poor water clarity despite correct chemical balance
• Short filter cycles between backwashes (less than 1 week)
• Cloudy water returns to pool during normal filtration
• Sand visible in pool (indicates cracked laterals or worn media)
• Filter more than 5 years old with original sand

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🔬 Filtration Performance

Metric	Value
Filtration Rating (Sand)	20-40 microns
Filtration Rating (Glass)	5-15 microns
Filter Area	0.125 m²
Filtration Velocity	50 m³/h/m²

Understanding Micron Ratings

Rating	What It Captures
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, bacteria clumps
Below 5 microns	Microscopic particles, most pathogens

💡 Note: Sand filters provide excellent everyday filtration. For crystal-clear spa-quality water, upgrade to glass media which captures particles down to 5 microns.

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⚙️ Valve Positions & Functions

The 6-way multiport valve provides complete control over your filtration system:

Position	Function	When to Use
Filter	Normal filtration operation	Daily use – water flows through sand bed
Backwash	Reverse flow to clean media	When pressure rises 0.5 bar above baseline
Rinse	Settle media after backwash	Always after backwashing – run 30-60 seconds
Waste	Bypass filter, drain to waste	Lowering water level, vacuuming heavy debris
Recirculate	Bypass filter, return to pool	Distributing chemicals quickly
Closed	Stop all water flow	When opening pump strainer basket

⚠️ Important: Always switch off the pump before changing valve positions to prevent damage to the valve and internal components.

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🎯 Ideal Applications

Application	Pool Size	Notes
🏠 Small residential above-ground	Up to 18,000 L	✅ Perfect match
🏠 Intex/Bestway pools	10,000-18,000 L	✅ Excellent upgrade from cartridge filters
🏠 Small in-ground residential	Up to 18,000 L	✅ Suitable for compact pools
🏊 Swim spas	Up to 15,000 L	✅ Good for swim spa applications
🧖 Large hot tubs	2,000-5,000 L	✅ Can be used with extended plumbing

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❓ Frequently Asked Questions

Q: What size pool will the FBT400 filter handle?

A: The FBT400 is designed for pools up to 18,000 litres (approximately 4,000 gallons). With its 6 m³/hr flow rate, it can turn over an 18,000 litre pool in just 3 hours, providing excellent filtration performance.

Q: How often do I need to backwash the filter?

A: Backwash when the pressure gauge reads approximately 0.5 bar (7 PSI) above your clean baseline reading. Typically this occurs every 1-2 weeks during the swimming season, but frequency depends on pool usage and debris levels.

Q: What type of filter media should I use?

A: The FBT400 is compatible with silica sand (0.5-0.7mm grain size), glass media, or zeolite. The filter requires approximately 35 kg of media. Glass media is recommended for superior filtration and longer service life.

Q: How long does filter sand last?

A: Standard silica sand should be replaced every 3-5 years. Glass media can last 8-10 years or longer with proper maintenance.

Q: What pump do I need for this filter?

A: Match the filter with a pump delivering 4-6 m³/hr. The pump flow rate should never exceed the filter’s maximum rated flow of 6 m³/hr to prevent damage and ensure effective filtration.

Q: Is sand included with the filter?

A: No, filter sand is sold separately. You will need approximately 35 kg of 0.5-0.7mm silica sand or equivalent glass media.

Q: Can I use this filter with a salt chlorinator?

A: Yes, the HDPE construction is resistant to salt water and compatible with salt chlorination systems.

Q: What warranty is included?

A: Please contact Parts4Tubs for full warranty details and terms.

📥 Downloads & Resources

📄 Installation & Maintenance Manual – Complete installation guide and operating instructions

💡 Tip: We recommend downloading and reading the installation manual before beginning installation to familiarise yourself with the requirements and procedures.

🏆 Why Choose the FBT400 Brasil Filter

✅ Reliable Filtration Performance – 6 m³/hr flow rate delivers effective water circulation for pools up to 18,000 litres

✅ Durable HDPE Construction – Blow-moulded tank resists UV damage, chemicals, and weather for years of reliable service

✅ Easy Operation – Top-mounted 6-way valve puts all controls within easy reach

✅ Low Maintenance – Simple backwash process and long-lasting sand media minimise upkeep requirements

✅ Perfect Size for Smaller Pools – Compact 400mm diameter suits above-ground pools and smaller in-ground installations

✅ Complete Package – Includes valve, pressure gauge, and drain valve – just add sand and connect

✅ Excellent Value – Quality Certikin engineering at an affordable price point

🤝 Why Buy From Parts4Tubs

✅ UK-Based Company – Local support from pool equipment specialists

✅ Fast UK Delivery – Quick dispatch to get your pool running

✅ Expert Technical Advice – Our team can help with sizing and installation questions

✅ Competitive Pricing – Great value on quality pool equipment

✅ Full Warranty Support – We stand behind the products we sell

✅ Easy Returns – 30-day return policy for peace of mind

✅ Complete Range – Filter media, spare parts, and accessories all available

💦 Summary

The Certikin FBT400 Brasil Top Mount Sand Filter is the ideal filtration solution for smaller residential and above-ground pools up to 18,000 litres. With its durable blow-moulded HDPE construction, convenient top-mounted 6-way multiport valve, and 6 m³/hr flow rate, this filter delivers reliable, low-maintenance performance season after season. The compact 400mm diameter makes it perfect for tight plant rooms, while the integrated pressure gauge ensures you always know when backwashing is needed. Order today and enjoy crystal clear pool water with minimal effort.