There are 3 factors to consider when choosing the best size Berkey water filter system for your needs:

1. How many gallons of water do you consume per day? According to research conducted by the USDA average person (154 lbs.) should consume about 1/2 a gallon of water per person per day. Which is why you commonly hear to drink 8 - 8oz. glasses of water per day. 8x8=64oz. exactly 1/2 a gallon. During hot weather or for Persons who are very active or elderly should consume more. The 1/2 gallon of water per person per day rule is the water you need just for drinking during normal activity periods.

Most of our customers find that once they start using their system they also like to use the filtered water for cooking. Cooking with water from your Berkey water filter basically doubles your use to 1 gallon of water per person per day. We at Berkey filters have found that after many years of customer feedback that this is the number that is most accurate for most of our customers 1 gallon of water per person per day.

2. What is the holding capacity of the system? The larger the holding capacity of the filter system the more reserve use you will have for peak consumption needs. For example: if you had a Travel Berkey (holds 1.5 Gal.) and While you were cooking dinner on a hot day your children came in the house after being outside with their friends and together they drank 6- 8 oz glasses of water (.4 Gal.). You need to make iced tea ( 1 Gal.) and you need water to boil pasta ( 1 gal.) that is a total of 2.4 gallons. Your travel Berkey only holds 1.5 gallons. You want to make sure the the holding capacity of the filter system you choose holds enough for your peak water consumption needs.

3. What is the flow rate of the different Berkey water filter systems? The more filters your unit has, the faster your unit will produce water and the faster it will recover from peak or sustained water needs. The taller the system the more water pressure that will generated also increasing the flow rate. The numbers shown on the chart below are when the unit is completely full. The flow rate will decrease as the level of water in the upper chamber falls.

4. What size Berkey system would be best for my needs? After years of customer feedback and field testing, we found that if you take the flow rate of the system and multiply that by the holding capacity, this number is a good indicator of the maximum number of people that each system would support under normal conditions. If you feel the your water needs are more than normal or if you plan on using the water filter for anything other than drinking and cooking, we suggest that you purchase the next size larger system than indicated on the chart below. All units produce the same quality of water.