Eaglesorb ES3 Anti-Scale Water Filter Cartridge

Scale is what hard water leaves behind: the white crust on faucets and showerheads, the chalky layer inside kettles and coffee makers, and the buildup on water heater elements that makes them work harder. You can stop most of it without salt, without a drain line and without taking the minerals out of your water.

The Crystal Quest Eaglesorb ES3 Anti-Scale Water Filter Cartridge does exactly that. It is filled with Eaglesorb ES3, Crystal Quest's own salt-free anti-scale media, in a drop-in cartridge. Instead of removing calcium and magnesium, it changes how they behave, so they pass through your plumbing instead of sticking to it.

At a glance

• Salt-free scale control: no salt, no brine tank, no regeneration and no wastewater
• Keeps the minerals: calcium and magnesium stay in your water; nothing is added
• Protects heating surfaces, fixtures and appliances from new scale, and existing scale slowly dissolves over time
• Crystal Quest's own media: Eaglesorb is our media brand
• Four sizes for countertop, under-sink and whole house housings

What you are looking at

Each cartridge is packed with Eaglesorb ES3, the active anti-scale media, sealed in a standard cartridge format for slim and Big Blue housings. There are no electrical parts and nothing to refill; water simply flows through the media bed. Each end cap has 1-micron pads behind its openings.

How an anti-scale cartridge works

Why hard water forms scale

Hard water carries dissolved calcium and magnesium. When that water is heated, or when it sits and dries on a surface, the minerals come out of solution as calcium carbonate and grow into a hard crust that bonds to metal, glass and porcelain. Heat speeds this up, which is why water heaters, kettles and coffee makers scale first.

Crystals that do not stick

Eaglesorb ES3 works as a catalyst. As water passes over the media, its surface pulls dissolved calcium and magnesium out of solution and turns them into tiny, stable crystals. Those crystals are already in their final mineral form, so they have no reason to grow onto pipes, fixtures or heating elements. They are small enough to travel through the plumbing with the water and rinse away.

Old scale, too

With the scale-forming minerals tied up as stable crystals, the treated water stops adding to existing deposits. Over time, buildup already in pipes and on fixtures slowly dissolves back into the water.

What anti-scale does not do

ES3 does not soften water. A hardness test reads about the same before and after, because the minerals are still there. Water left to dry on a surface can still leave spots. What ES3 changes is the hard, bonded scale that clogs fixtures and coats heating elements.

What it does

Primary job: reduces scale buildup from hardness (calcium and magnesium) on fixtures, appliances and heating surfaces, without salt.

Requires pretreatment for: iron, manganese, copper, oil, hydrogen sulfide and phosphate, and chlorine above 3 ppm. These coat the media's active surface or interfere with crystal formation, so remove them ahead of the ES3 stage.

Not designed to treat: it is not a filter for contaminants. It does not remove chlorine, chemicals, heavy metals, bacteria or viruses. Pair it with sediment, carbon or SMART stages for filtration.

Is it right for my water?

On city water, salt-free anti-scale is our usual recommendation for scale control. Test your hardness first. At 25 grains per gallon or more in a home, a salt-based softener does the job better; see the Whole House Water Softener or, for a single point of use, the Cation Resin Filter Cartridge. If your water carries iron, manganese, sulfur smell or high chlorine, plan the pretreatment stages first.

For whole home scale control from a tank, the Crystal Quest Salt-Free Water Conditioner uses Eagle anti-scale media with sediment, carbon and ultrafiltration stages.

Why Crystal Quest

• Our own media. Eaglesorb is Crystal Quest's media brand, and salt-free anti-scale media is at the heart of our salt-free systems.
• Honest about limits: clear pretreatment requirements and a clear line between conditioning and softening.
• Both paths to less scale: salt-free ES3 and true softening, so you get the right one for your water.
• Over 1,000,000 people served since 1994. Crystal Quest builds under ISO 9001 quality management, has made water filtration in the USA for over 30 years and offers lifetime support by phone, email or chat.

Where it fits

• Countertop and under-sink systems that take the 2-7/8" x 9-3/4" size, to protect a drinking water line, kettle or coffee maker.
• Whole house cartridge systems with slim 20" or Big Blue housings, after any sediment, iron or carbon stages your water needs.

Choose the size printed on your current cartridge or in your order history: 2-7/8" x 9-3/4" (CQE-RC-04113), 2-7/8" x 20" (CQE-RC-04114), 4-5/8" x 9-3/4" (CQE-RC-04115) or 4-5/8" x 20" (CQE-RC-04116).

Common questions

Eaglesorb ES3 anti-scale cartridge specifications

Published ratings apply to the selected cartridge and listed conditions.

Media and treatment