All the Berkey counter-top systems rely on gravity to push the water through the Berkey elements. Water molecules passing through the “Tortuous Path” structure of the Black Berkey water purification elements, are drawn gently by gravity and stay in contact with the filter element for an extended period of time. This allows the filter elements to be more efficient in capturing contaminates, as opposed to most competing filtration systems. The greater the volume of the water and the number of Black Berkey Filter Elements, the faster the flow rate of purified water. The table below shows the flow rate of purified water per system configured with the standard 2 filters and when the same system is fully expanded.
Read our complete overview of all the Berkey models and their flow rates.
|Berkey Model||Flow*/hour with 2 Filter Elements||Fully Expanded Flow*/hour|
|Travel Berkey||~10.4 liters||N/A|
|Berkey Light||~16 liters||~32 liters|
|Big Berkey||~13.2 liters||~26.5 liters|
|Royal Berkey||~15.1 liters||~30.2 liters|
|Imperial Berkey||~20.8 liters||~62.5 liters|
|Crown Berkey||~24.6 liters||~98.4 liters|
*Flow rates are calculated with upper chamber full to top. Flow rate decreases as water level declines. As it is impractical to keep the upper chamber completely full at all times, the flow rates are in practice less than the stated optimal rate.
For a complete description of how the Black Berkey Filter Elements work: Click Here
The best guideline for choosing which size is appropriate for you is that bigger is usually better providing you have the space for it. Which simply means that it's more convenient to have a larger system as you won't have to fill it as often. Since the higher water volume in the upper chamber increases the pressure upon the filters the water therefore flows through faster. The differences in cost between the various models are minimal when you consider that you will be using the same model for 10-20+ years.
|Berkey Model||Capacity||Number of People|
|Travel Berkey||5.7 liters||1 - 2 people|
|Berkey Light||10.4 liters||2 - 5 people|
|Big Berkey||8.5 liters||1 - 4 people|
|Royal Berkey||12.3 liters||2 - 6 people|
|Imperial Berkey||17 liters||4 - 8+ people|
|Crown Berkey||22.7 liters||4 - 12+ people|
As has already been mentioned, all the Berkey Water Filter systems come configured with 2 upper chamber filters, the Black Berkey Filter Elements. The filtration quality will not be improved by increasing the number of filters used in the upper chamber, but it will increase the speed of filtration and the volume of water that can be filtered. For instance, by increasing the number of Black Berkey elements from 2 to 4, the filtration speed and volume of water that can be filtered will approximately double from 22,700 total liters to 45,400 total liters.
Especially for residents of Ireland and parts of England and Spain we offer the lower chamber PF(Post Filtration)-2 Fluoride & Arsenic filters. The PF-2 filters are designed to work together with the Black Berkey filters and are easily installed. The PF-2 filters should be replaced every 3,785 liters or once a year whichever comes first.
View the complete information about the PF-2 Fluoride & Arsenic Filters