With a wide range of water filters available on the market, it may be difficult deciding on which product is best for you. In this series of articles we will discuss what to look for when purchasing a water filter, and compare the Berkey filters to other water filters on the market to see how they stack up against their competitors. When comparing water filters we need to ensure that we are comparing apples with apples. Comparing a lightweight portable water filter bottle with a countertop unit that serves a family simply wouldn't be a fair comparison to either unit, so we will strive to compare gravity water filters of similar size and capabilities to help you make an informed decision when making your purchase.
Our first contender in this series are the Big Berkey Water Filters versus Katadyn Gravidyn, so lets have a look at how they compare:
An image of a Big berkey with a glass of water
System Filtration Capabilities
Water filters can either be classified as water purifiers or water filters. What's the difference you ask? Water filtration by definition simply means to strain out the impurities from a water source. The first classification is a water filter, to meet this standard a water treatment device must remove at least 99.99% of pathogenic bacteria. This is known in the water filter industry as a log 4 reduction. The second classification is a water purifier, to meet this standard a water treatment device must remove at least 99.9999% of pathogenic bacteria (log 6 reduction). In addition the water purifier must be capable of reducing viruses by at least 99.999% (log 5 reduction). The Katadyn is classified as a water filter, and the Big Berkey is classified as a water purifier.
While many water filters are capable of filtering out a wide range of contaminants, such as chlorine, heavy metals, and toxic chemicals, the Big Berkey filter will remove all these pathogens, including tiny viruses that the Katadyn Gravidyn is not capable of removing. Berkey filter systems (including the Big Berkey) are the only gravity fed water filters that meet the standards set in order to be classified as water purification systems. In addition, the Big Berkey can be fitted with post filters in the lower chamber to remove additional contaminants, such as arsenic and fluoride, that standard filter elements are not capable of removing. The Katadyn Gravidyn does not have this capability.
Advantage: Big Berkey
Water Output
The Big Berkey produces a maximum of 84 gallons per day with the standard 2 element system compared to a maximum of 24 gallons a day produced by the Katadyn Gravidyn. The Big Berkey can be expanded with additional filter elements (total of 4) to improve performance further, providing a maximum of 168 gallons a day allowing it to support more people.
Advantage: Big Berkey
Affordability
The initial cost of the Big Berkey is slightly higher at $278 compared to $220 for the Katadyn Gravidyn, however the Berkey is more economical to run and maintain in the long run. While the replacement costs of the filter elements are similar ($60/filter for the Berkey and $56/filter for the Gravidyn), the Big Berkey is fitted with two filter elements (standard) while the Gravidyn is fitted with three, which will all need to be replaced simultaneously. The savings become even more apparent when one examines the replacement intervals – the Gravidyn filter elements need to be replaced every six months, while there is no replacement time limit for the Berkey.
Working on the assumption that the three elements in the Gravidyn will deliver 12 gallons in a 12-hour day over 182 days (the recommended six month time limit), each element is capable of delivering 730 gallons before it needs to be replaced. Compare this to the Berkey, which has no time limitation, with the maximum output per filter element estimated to be around 3000 gallons. Based on the maximum daily outputs and recommended replacement time limitations, the overall operating cost equates to approximately 1.7 cents per gallon for the Berkey compared with 7.6 cents per gallon for the Gravidyn – the Big Berkey is clearly much more economical to run.
Advantage: Big Berkey
Versatility (Setup and Portability)
Both units are freestanding gravity filters that operate without the need for electricity or plumbing, making them easy to set up and move around. There is not much difference in the weights of the units – the Big Berkey is slightly heavier, weighing around 9 pounds as opposed to the Katadyn's 6.5 pounds. When turned on it's head, the upper chamber of the both units will fit snugly inside their lower chambers, reducing the overall size to aid portability.
Advantage: Neither
Viewable Water Level
The Katadyn Gravidyn is semi-translucent, allowing the user to visibly see the water level within the unit to facilitate topping up when necessary. The stainless steel chamber of the Big Berkey is opaque and therefore prevents the user from being able to quickly see when the chamber needs to be refilled. However, it is possible to purchase an optional sight glass spigot as an upgrade, which allows water levels to be easily viewed on a tube indicator, but there is an extra cost involved. If this is an issue, you could opt for a Berkey Light system ($243), which is made of clear plastic, and has the same filtration capabilities as the Big Berkey.
Advantage: Neither
Safety
The Big Berkey is manufactured from spun 304 stainless steel while the Katadyn Gravidyn is constructed from molded silicon. Both units are made from food grade materials that will not leach chemicals or toxins into the water.
Advantage: Neither
Aesthetic Design
The stylish stainless steel Big Berkey will look good in any kitchen, whereas the plastic Katadyn Gravidyn lacks the classy finish of the Berkey.
Advantage: Big Berkey
Durability
The spun 304 stainless steel Big Berkey is designed to be durable, however, it may suffer a dent if dropped. The silicon Katadyn Gravidyn has a slight advantage here, as it will not dent if it takes a knock. Again, the Berkey Light offers an alternative to the Big Berkey if this is a concern, evening the score.
Advantage: Neither
Warranty
While the Katadyn may be slightly tougher than the Big Berkey, the Berkey comes with a 6 month manufacturers guarantee against part defects, a 2 year manufacturers prorated warranty on the filters, and a lifetime BigBerkeyWaterFilters.com warranty on the stainless chambers, spigots, and hardware. The Katadyn Gravidyn offers a 2 year guarantee.
Advantage: Big Berkey
Verdict
If you are looking for a stylish, cost effective, top of the range water purifier that is capable of removing most contaminants and pathogens, including microscopic viruses, then a Berkey is your best bet.
