Waimana 20 Inch Jumbo Carbon Block Filter - 5 Micron, Chlorine & Taste Removal NZ

A 5 micron activated carbon block cartridge for 20 inch jumbo housings. The Waimana 20CTO05 removes chlorine taste and odour from your water — the stage that makes the biggest difference to how your water tastes and smells at every tap.

The 20 inch jumbo format delivers a higher flow rate of 75 L/min and greater carbon capacity than a 10 inch cartridge — the right choice for larger homes and high-demand installations. Like all carbon block cartridges, it also catches fine sediment as a secondary function at 5 micron.

Waimana is our value cartridge — solid quality, fair price, no frills.

Key specs at a glance

• Micron rating: 5 micron
• Size: 20 inch jumbo (20" x 4.5")
• Flow rate: 75 L/min
• Material: Activated carbon block (polypropylene core and end caps)
• Operating temperature: 5–45°C
• Pressure range: 1–4 bar
• Not reusable — replace when taste returns or flow drops
• Sold as: Single cartridge

Why choose the Waimana 20CTO05

• Removes chlorine taste and chemical odour from mains and tank water
• 5 micron rating also catches fine sediment as a secondary function
• Activated carbon adsorbs organic compounds — not just physical filtration
• 75 L/min flow rate suits larger homes and high-demand installations
• Greater carbon capacity than a 10 inch cartridge — longer service life
• Fits most 20 inch jumbo housings — compatible with Trevoli, Pentair, Puretec, and other major brands
• Food-grade construction — safe for use in drinking water systems
• Great value — reliable performance at a straightforward price

How it works

Activated carbon has an enormous surface area at the microscopic level. As water passes through the carbon block, chlorine, chemical compounds, and organic taste and odour molecules are adsorbed onto the carbon surface and removed from the water. This is a chemical process — not just physical trapping — which is why carbon blocks are so effective at improving taste and smell.

The carbon is consumed over time as the adsorption sites fill up. When the carbon is exhausted, taste and odour will return even if flow rate is still good. That's the signal to replace the cartridge — not just pressure drop.

Carbon block cartridges are not designed to be cleaned and reused.

Technical specifications

Compatible with

Fits most 20 inch jumbo housings (20" x 4.5"), including:

• Trevoli whole house systems
• Pentair housings
• Puretec housings
• Waiora Ultra II and Ultra III UV systems
• Other 20 inch jumbo housings (4.5 inch diameter cartridge)

Not suitable for 20 inch standard housings (2.5 inch diameter) or 10 inch housings. Check your housing takes a 20 inch x 4.5 inch cartridge before ordering.

Frequently asked questions

What does a carbon block filter actually do?

It removes chlorine, chemical compounds, and organic tastes and odours from your water. Activated carbon works through adsorption — compounds bond to the carbon surface and are removed from the water as it passes through. The 5 micron rating also catches fine sediment as a secondary function.

How is a carbon block different from a sediment filter?

Sediment filters physically trap particles. Carbon blocks do that too, but their primary function is chemical — removing taste and odour compounds through adsorption. If your water smells or tastes of chlorine, a carbon block is what addresses it. A sediment filter alone won't.

How is the 20 inch version different from the 10 inch?

The 20 inch jumbo format contains more carbon media — this means a higher flow rate (75 L/min vs 40 L/min), greater carbon capacity, and longer service life. It's the better choice for larger households and high-flow installations.

How often do I need to replace it?

We recommend replacing every 6–12 months depending on your water quality and usage. The clearest signal for a carbon block is taste and odour returning — not just a pressure drop. If your water starts tasting or smelling of chlorine again, it's time to replace the cartridge.

Can I clean and reuse this cartridge?

No. Carbon block cartridges are not reusable. The activated carbon is consumed as it adsorbs compounds from your water — rinsing won't restore it. Replace when taste returns or flow drops.

Will it fit my housing?

It fits most 20 inch jumbo housings — these take a cartridge that's 20 inches long and 4.5 inches in diameter. If you're not sure of your housing size, measure the inside diameter before ordering. Get in touch if you're not sure.

Do I need a sediment filter before the carbon block?

Yes, in most cases. A carbon block works best when the water entering it is relatively clear. In high-sediment water, a polyspun or pleated sediment filter upstream will protect the carbon block and extend its life. Most whole house systems use sediment stages before the carbon block for this reason.

Do I need special tools to change the cartridge?

Just the housing wrench that came with your system. Shut off the water first, unscrew the housing, swap the cartridge, and reinstall. A quick rinse of the housing while it's open is good practice.

Is it suitable for drinking water?

It's made with food-grade materials and is suitable for use in drinking water systems. The spec sheet cautions that it should not be used with microbiologically unsafe water without adequate disinfection — so if your water source carries biological risk, pair it with a UV system downstream.

What warranty applies?

Filter cartridges are consumables and don't carry a standard product warranty. If you receive a cartridge that is visibly damaged or defective, get in touch and we'll sort it out.