Berkey vs. Doulton Water Filters

We live in a contaminated world. Human activity has an increasingly problematic effect on our water supply. A look at the water quality report in some localities can be scary indeed. No wonder there is such a proliferation of water purification systems to choose from. Some, of course, are better than others. That’s why we want to help you educate yourself in order to parse out which option is right for you. Below, we are comparing the Big Berkey Water Filter to Doulton brand filters.

Doulton Filters

Doulton is a very old company that has been making filters for a long time. They are based on a technology discovered in ancient times that clay pots are porous. They can actually leak through the fired clay itself. When people saw that the water leaking out of a pot was cleaner than the water inside, it gave birth to what is known as the “Ceramic” filter. At first, these were simply a clay vessel suspended over a receptacle to catch the water that dripped out the bottom.

In 1827, Henry Doulton invented a filter that placed a long, skinny version of the traditional pot, upside down in the bottom of a tank, so that the water flowed into the pot, rather than out of it. This gave some advantages in terms of cleaning the filter and made it replaceable. It is because of this thin shape that Doulton refers to their filters as “candle” filters.

The Doulton company produces filters for various applications including industrial filters and doesn’t specialize in the kind of home models that Berkey does. However, a couple of the Doulton countertop models are somewhat similar to Berkey filters.

Berkey Vs Doulton

How They Work

Like other filters, ceramic filters consist of a porous material with pores large enough to permit water to pass through, but small enough to exclude many contaminants and some microorganisms. Because they are hollow, candle filters can be filled with media to make up for some of what the ceramic shell doesn’t catch. When the pores become clogged, ceramic filters can be scrubbed clean a certain number of times before they need to be replaced.

What They Remove: Doulton

Ceramic filters do fairly well at removing many contaminants such as chemicals, pesticides, chlorine, VOC’s, and the larger pathogenic microorganisms, such as bacteria and cysts. Viruses, however, are far too small to be trapped in the pores of a ceramic filter. Heavy metals are not filtered out by the ceramic filter, but Doulton does provide post filters to address them. Like the Berkey, Doulton requires a post-filter to remove fluoride.

Pros Cons
✔ Lower initial cost
✖️ Shorter life of the filter elements 
✖️ Higher per-gallon cost
✖️ Requires post-filter for heavy metals
✖️ Does not remove viruses

Berkey Filters

Berkey Filters began in the 1990’s as a family business. While Berkey water filter systems didn’t exactly get started way back in the Georgian era, we are proud of our generation-long track record of providing technologically advanced water purification systems.

Berkey filters work somewhat like the Doulton filters mentioned above in that they are both gravity water filters that slowly percolate water from one chamber to another through an element. However, rather than an age-old technique, the Black Berkey element at the heart of the Berkey system is based on a proprietary mix of high-tech media that achieves what virtually no other filter can.

Berkey specializes in home use filters for drinking water. We make eight different units, all of which are domestic purification systems.

Berkey vs Doulton

How They Work

The outer shell of the Black Berkey is composed of a proprietary and very specialized blend of six different types of media, compacted into a tight matrix. This matrix forces water to slowly squeeze through microscopic pores and meandering tunnel-like microfissures in what we refer to as a “tortuous path,” excluding sediment, bacteria, cysts, parasites, and other pathogens. This aspect of Berkey purification is known as microfiltration.

The second facet of the Black Berkey’s purification is absorption. This works a little bit like the everyday sense of the word, as in cereal that absorbs milk, or a cloth absorbing a spilled drink. A body of material takes some free-moving substance and pulls it into itself, sequestering it there. Absorption in the Black Berkey, however, works on the principle of ion-exchange, where contaminants with a strong negative charge are taken out of solution and into the media in the filter, where they become chemically bonded with it. This is how Berkey filters remove heavy metals like chromium, cadmium, lead, copper, aluminum, and mercury.

Finally, the Black Berkey filter employs adsorption. If absorption (mentioned above) is akin to a paper towel soaking up a spill, think of adsorption as being more like static cling. Just like electrostatic forces make your clothes wad up and packing peanuts stick to your hand, they are also at work in the microscopic world. Unlike bacteria, which are huge by comparison and can be filtered out, viruses are small enough to sneak into the tiniest of micropores. However, as they move into the filter, viruses are electrostatically drawn out of the water by an attraction known as Van der Waals forces and held against the surface of the media permanently. This is how Berkey filters can eliminate 99.9999% of all viruses.

What They Remove: Berkey

Filters remove the same contaminants as ceramic filters do through microfiltration, like rust, turbidity, bad tastes and odors, bacteria, parasites, pesticides, herbicides, VOC’s and other chemicals. They go beyond these in removing MTBE, lead and other heavy metals, 99.9999% of viruses and do a better job of removing chlorine.

Pros Cons
✔ More contaminants removed
✖️ Slightly higher startup cost
✔ Higher percentage of bacteria removed
✔ Removes viruses
✔ Higher output
✔ Longer filter element life
 
✔ Lower cost per gallon

Head-to-Head

To make a fair comparison, here we have chosen two filters that are roughly similar in design and capacity. From Doulton, the Imperial Supersterasyl 2x, and from Berkey, the Big Berkey Water Purifier. Both of these are countertop models made from high-quality food-grade 304 stainless steel, plasma welded and safe for contact with drinking water. Both are gravity water filters that can use either two or four filter elements. Here we are comparing the standard 2-element installations for both models.

 Features The Doulton Imperial 2x The Big Berkey
Volume 2.25 Gallons 2.25 Gallons
Cost $219 $278
Contaminants Removed 99.99% of bacteria and cysts, sediments, pesticides, solvents, & chlorine 99.9999% of bacteria  and cysts, sediments, pesticides, solvents, chlorine, PLUS viruses and heavy metals
Materials 304 Stainless Steel
304 Stainless Steel
Purification Speed 20 gallons per day 84 gallons per day
How the Filters Work Microfiltration Microfiltration, Adsorption, and Absorption
Filter Lifespan 1,500 gallons 6,000 gallons
Warranty 1 Year against defects / workmanship

Lifetime Warranty on Stainless Steel Units - all parts & pieces

2 Year Pro-rated on Black Filters

6 Month on everything else

Bottom Line

If you spend a moment looking at the relative benefits of Doulton and Berkey water filters, we think the outcome is pretty obvious. In every area but initial cost, Berkey filters are either equal or superior to Doulton. Even in cost, however, when you do the math over the life of the filter, Berkey is the cheaper long-term option. When you factor in the shorter lifespan of the Doulton filter elements, the Doulton price-per-gallon comes out to over 6 cents a gallon. Berkey’s per-gallon cost: 4 cents.

Doulton may be something of a heritage company in the water filter business, but a newer, more polluted world requires newer, more advanced technology. If you want the most convenient source for the safest drinking water you can get at the lowest overall price, the choice is clear. Berkey purification systems are number one.

Related Articles

Berkey vs Brita

Berkey & Brita which filtration option is best?

Berkey vs Katadyn

Compare Berkey and Katadyn Water Filters