Big Blue Water Filters: Complete Buyer’s Guide

How to Compare 10- and 20-Inch Cartridges, Single, Duplex, Triplex and UV-Equipped Systems

Quick answer A Big Blue-style housing accepts a wide 4.5-inch cartridge. Choose the housing length, number of stages, cartridge media, and micron rating based on tested water conditions and the required peak flow. Add UV only when microbiological risk and the selected system's rating justify it.

A Big Blue water filter can protect plumbing, appliances, and downstream treatment from suspended sediment. With the correct cartridge, it can also reduce chlorine-related taste and odour.

However, the housing does not determine what the system treats. Its results depend on the cartridge, water chemistry, flow, and maintenance.

This guide explains how to compare the Big Blue housings, cartridges, and UV-equipped systems available from Cleanflow.

What Is a Big Blue Water Filter?

Big Blue commonly describes wide filter housings that use cartridges approximately 4.5 inches in outside diameter. Cleanflow carries compatible housings and cartridges in nominal 10- and 20-inch lengths.

The wider cartridge provides more room for filter media than a standard 2.5-inch cartridge. Actual flow, dirt capacity, and service life still depend on the chosen cartridge and operating conditions.

Compatibility check Match the cartridge diameter and nominal length to the housing. Also confirm the end configuration, gasket, temperature limit, and manufacturer specifications before ordering.

What Can a Big Blue System Treat?

A Big Blue housing is a pressure vessel for a replaceable cartridge. It does not remove a contaminant until suitable media is installed.

Water concern	Typical Big Blue role	Important limit
Sand, silt and particulate rust	A sediment cartridge can capture suspended particles within its rated range.	A lower micron rating may clog faster or reduce flow.
Chlorine taste and odour	A verified carbon cartridge may reduce chlorine and improve taste or odour.	Capacity, flow, and claims vary by cartridge.
Oxidized iron particles	Sediment filtration may capture particles large enough for the selected cartridge.	Dissolved iron usually needs oxidation and dedicated treatment.
Hardness	Standard sediment and carbon cartridges do not soften water.	A water softener normally treats calcium and magnesium hardness.
Dissolved salts or TDS	Standard cartridges are not designed for broad dissolved-solids reduction.	Reverse osmosis or another suitable process may be required.
Microorganisms	A properly selected UV system can provide microbiological disinfection after pretreatment.	A housing or ordinary sediment cartridge is not a disinfection system.

Should You Choose a 10- or 20-Inch Housing?

Housing length affects cartridge size, installation space, and potential media capacity. It should not be chosen from bathroom count alone.

Factor	10-inch housing	20-inch housing
Space	More compact and easier to fit in tight utility areas.	Requires more wall height and service clearance.
Cartridge capacity	Uses the smaller cartridge in the same product family.	Often contains more media or filtration area.
Service interval	May require more frequent service under the same sediment load.	May run longer under comparable conditions, but water quality controls the result.
Flow selection	Can serve suitable point-of-entry applications when cartridge pressure loss is acceptable.	Often selected for higher demand or capacity, subject to complete-system ratings.
Cost	Usually lower initial cartridge and housing cost.	Usually higher initial cost but potentially fewer service events.

Before choosing, calculate peak simultaneous demand. Then check source pressure, port size, cartridge data, and expected pressure loss.

Do You Need a Single, Duplex or Triplex System?

Single, Duplex, and Triplex describe the number of cartridge housings. Duplex and Triplex systems place their treatment stages in series.

Configuration	What it provides	Consider it when
Single	One cartridge and one primary treatment stage.	One cartridge can address the confirmed goal, or the housing serves as pretreatment.
Duplex	Two cartridges in sequence.	You need coarse-to-fine sediment treatment or sediment followed by carbon.
Triplex	Three cartridges in sequence.	You need three distinct stages: greater sediment staging or sediment plus carbon treatment.

Flow reminder Adding housings in series adds treatment stages. It does not automatically increase flow. Every cartridge adds some resistance, which rises as sediment accumulates.

Which Big Blue Cartridge Should You Use?

Select cartridge construction after identifying the water problem. Micron rating alone does not tell you how a cartridge is built or what it can treat.

Cartridge type	Construction and role	Consider it when
Spun or melt-blown polypropylene	Bonded polypropylene fibres provide disposable depth filtration.	You need general sediment filtration without a washable cartridge.
String wound	Polypropylene yarn is wound around a rigid core to create filtration depth.	Sediment is mixed or changes from coarse to finer particles.
Pleated	Folded media provides a larger exposed surface area.	Maintaining flow and possible rinsing matter, where the cartridge permits reuse.
Dual gradient	A coarser outer zone protects a finer inner zone.	Heavy or variable sediment clogs a single-gradient cartridge too quickly.
Carbon block	Compressed activated carbon provides advertised chlorine, taste and odour reduction.	Municipal chlorine or aesthetic taste and odour are confirmed concerns.
GAC	Loose granular activated carbon adsorbs selected compounds.	The product's capacity and pressure-loss data match the application.

Cleanflow carries current Franklin FWPS spun polypropylene cartridges, FWSW string-wound cartridges, and FWCB carbon blocks in Big Blue sizes.

Which Micron Rating Should You Choose?

A micron rating indicates the particle size a cartridge is designed to reduce under stated test conditions. Confirm whether a rating is nominal or absolute before comparing products.

Rating	General selection use	Trade-off
50 micron	Coarser visible sediment or an initial protective stage.	Does not capture finer suspended material.
20 micron	General visible sediment or the first stage in a graded sequence.	Finer particles can pass through.
5 micron	Finer silt and smaller suspended particles.	May load faster in dirty water.
1 micron	Very fine particulate treatment when the application requires it.	Can create greater restriction and shorter service life.

Do not automatically select the smallest number. Start with water testing and particle conditions, then balance capture, pressure loss, and service frequency.

Which Cartridge Should Go First?

Water normally moves from coarser pretreatment toward finer or adsorptive treatment. The correct order protects downstream media and reduces avoidable pressure loss.

System	Example sequence	Purpose
Single	One cartridge matched to the confirmed treatment goal.	One-stage filtration or protection for downstream equipment.
Duplex sediment	Coarser sediment → finer sediment.	Progressive particle reduction.
Duplex mixed treatment	Sediment → verified carbon cartridge.	Protects carbon from unnecessary sediment loading.
Triplex sediment	20 micron → 5 micron → 1 micron, when testing supports that sequence.	Progressive sediment capture.
Triplex mixed treatment	Coarse sediment → finer sediment → verified carbon cartridge.	Sediment control followed by taste and odour treatment.
UV-equipped	Required filtration and conditioning → UV chamber.	Improves water conditions before microbiological disinfection.

These are examples Do not use a standard cartridge sequence as a substitute for water testing. Iron, manganese, hardness, tannins, and microbiological concerns may require other treatment.

When Should You Add UV Disinfection?

Consider UV when testing or source vulnerability identifies a microbiological risk. Private well owners should follow their provincial or territorial testing guidance.

UV damages microbial genetic material and prevents susceptible organisms from reproducing. It does not remove sediment, hardness, dissolved salts, chlorine, or other chemicals.

• Use pretreatment that meets the UV manufacturer's incoming-water requirements.
• Select a rated UV flow that meets the building's peak simultaneous demand.
• Keep the quartz sleeve clean and replace the lamp as directed by the system timer and manual.
• Confirm the required certification and performance class for the intended water source.

Cleanflow's Waterite UV-equipped Big Blue listings combine two or three cartridge stages with an Excelight UV chamber. Listed features include a 304 stainless-steel chamber, quartz sleeve, lamp alarm, and 9,000-hour lamp rating.

Compare the current Duplex 10-inch UV system, Duplex 20-inch UV system, Triplex 10-inch UV system, and Triplex 20-inch UV system. Available variants and flow ratings can change, so confirm the selected listing before ordering.

How Should You Size a Big Blue System?

Size the complete treatment train, not the empty housing. A large housing cannot compensate for a restrictive cartridge or an undersized UV chamber.

1. Test the water. Identify suspended sediment, chlorine, hardness, iron, manganese, and microbiological concerns.
2. Calculate peak demand. Use expected simultaneous fixture flow, not average daily consumption.
3. Check pressure loss. Review every cartridge at the planned flow and allow for loading over time.
4. Confirm connections. Match the line size, housing ports, valves, and fittings to the installation.
5. Measure service space. Leave enough room below each sump to remove the housing and cartridge safely.
6. Check operating limits. Verify pressure, temperature, and indoor or freeze-protection requirements for every component.

Which Big Blue System Matches Each Need?

Product family	Available format	Selection role
Franklin FWHL	Single 10- or 20-inch housing; black or clear; 1-inch connections.	One treatment stage or pretreatment where the selected cartridge meets the objective.
Boshart housing kits	Single Big Blue-style housing with model-specific port options.	Compact single-stage installations; verify the exact kit and connection size.
Waterite Duplex	Two 10- or 20-inch housings in series.	Two-stage sediment treatment or sediment followed by carbon.
Waterite Triplex	Three 10- or 20-inch housings in series.	Three treatment stages or graded sediment followed by carbon.
Waterite Duplex or Triplex with UV	Cartridge stages followed by an integrated UV chamber.	Applications that require filtration plus appropriately selected microbiological disinfection.

Browse the full Big Blue Water Filters collection for current availability.

For a single housing, compare the Franklin FWHL Series.

For multiple stages, compare the Waterite Duplex 10-inch, Duplex 20-inch, Triplex 10-inch and Triplex 20-inch systems.

How Should You Maintain a Big Blue System?

Maintenance intervals vary with water quality, cartridge type, total use, and the manufacturer's instructions. A fixed calendar interval cannot cover every installation.

• Replace a sediment cartridge when pressure loss or reduced flow reaches the manufacturer's service limit.
• Replace carbon media at its rated capacity or when treatment performance declines, whichever comes first.
• Isolate and depressurize the system before opening any housing.
• Inspect the O-ring, sealing surfaces, and sump during every cartridge change.
• Use only the lubricant and tightening method allowed by the housing manufacturer.
• Keep UV equipment powered and serviced according to its manual, lamp timer, and alarm status.

Cleanflow carries a Waterite Big Blue housing wrench for loosening compatible sumps and replacement Waterite O-rings in single, duplex, and triplex pack quantities.

Which Buying Mistakes Should You Avoid?

• Choosing a 1-micron cartridge only because it sounds more thorough.
• Assuming the housing removes a contaminant without checking the installed cartridge.
• Using a carbon cartridge before controlling a heavy sediment load.
• Treating dissolved iron or hardness with an ordinary sediment cartridge.
• Selecting UV from bathroom count instead of peak flow and verified performance.
• Using a high-temperature cartridge inside a housing that is not rated for that temperature.
• Installing the housings without enough clearance for safe cartridge changes.
• Ignoring cartridge pressure loss when several stages operate in series.

How Can Cleanflow Help You Choose?

Before contacting Cleanflow, gather your water source, test results, peak flow, line size, available wall space, and treatment goals. These details help narrow the housing, cartridge, and UV options.

Browse all Big Blue Water Filters.

Product note Prices, inventory, product variants, and specifications can change. Confirm the current product page and applicable manual before purchase or installation.