Not all contaminants in drinking water are filtered in the same way. That is why our filters use different technologies – either individually or in combination – depending on whether the aim is to reduce pesticides and PFAS, remove particles, reduce limescale or provide an additional barrier against bacteria.

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1. Coconut-Based Activated Carbon Block – The Foundation of Our Drinking Water Filters

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Activated carbon primarily works through adsorption. This means that a wide range of organic substances bind to the extensive surface area of the activated carbon as water passes through the carbon block.

At the same time, the compressed carbon block acts as a physical barrier against particles. The filtration rating depends on the individual cartridge. For example, Oceano uses a carbon block with a nominal filtration rating of 0.5 microns (µm).

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Carbon block filtration is used to reduce, among other things:

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• Pesticides and herbicides

• Selected PFAS compounds, including PFOS, PFOA and PFNA

• Chlorine, chloramines and chlorination by-products

• VOCs and other organic compounds

• Pharmaceutical residues

• Selected heavy metals

• Microplastics and particles

• Sand, rust and sediment

• Unwanted taste and odour

 

An important advantage is that naturally occurring minerals in the water are not removed in the same way as with reverse osmosis.

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Used in: Ecoline AB22, the Ecoline Duo range, Oceano and the larger Acero filtration systems.

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2. Double Activated Carbon Block – Increased Filtration Capacity

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Filters such as the Ecoline Duo AB22+ use two separate carbon blocks in sequence.

The principle is the same as with a single carbon block, but the water comes into contact with a greater total amount of activated carbon and passes through two filtration stages. This can significantly improve the reduction of certain contaminants.​

This is particularly beneficial when enhanced carbon-based filtration is required for organic compounds, pesticides and selected PFAS compounds, including PFOA, PFNA and PFOS.

Ideal for: Households seeking enhanced carbon block filtration without a particular need for bacterial filtration or limescale reduction.

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3. 0.01 µm Ultrafiltration – The Physical Barrier

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Ultrafiltration works differently from activated carbon. Water passes through an extremely fine membrane with a pore size of 0.01 microns.

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The membrane acts as a physical barrier, retaining very fine particles and bacteria.

This is why Holmblad's Ultra filters combine activated carbon block filtration with ultrafiltration (UF). The carbon block primarily reduces chemical and organic contaminants, while the UF membrane provides an additional microbiological filtration barrier.

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Carbon block → PFAS, pesticides, chlorine, organic compounds, unwanted taste and odour, etc.

0.01 µm UF → Bacteria and very fine particles.

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This distinction is important: the UF membrane is not primarily responsible for reducing PFAS and pesticides. That is the function of the activated carbon block.

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Used in: Ecoline Duo Ultra and Ecoline Triple Ultra.

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4. Sediment Filters – Protection Against Sand, Rust and Larger Particles

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A sediment filter is a mechanical pre-filter. Water passes through a porous material that retains particles above a certain size.

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For example, the Ecoline Triple Ultra uses a 20 µm pre-filter before the activated carbon block and UF membrane.

This pre-filter retains sand, rust and larger particles while protecting the subsequent filtration stages against unnecessary clogging.

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Particularly relevant for:

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• Private boreholes

• Well water

• Older plumbing installations

• Water containing high levels of sediment or suspended particles

 

5. Anti-Limescale Filtration – Reducing Limescale Deposits

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Anti-limescale filtration serves a different purpose from activated carbon and ultrafiltration.

Its primary function is to reduce the tendency of dissolved calcium and magnesium salts to form hard limescale deposits on taps, heating elements, coffee machines and kettles.

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For this reason, several of our filtration systems combine anti-limescale media with activated carbon blocks, providing both the reduction of selected contaminants and protection against limescale deposits.

For example, Oceano combines a 0.5 µm coconut-based activated carbon block with polyphosphate technology to help reduce limescale formation and deposits.

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Used in: Ecoline Duo AL and Oceano.