What’s in a Filter?

At Home with + POOL

Estimated Time: 30 minutes

Subjects: Science, Math, 

Grade: 6-12

What You Need At Home: Brita filter (or any drinking water filter), utility knife, kitchen scale, light cup

One of the first things we did when we came up with + POOL was break apart a Brita filter.  We had no idea what they were made of and how they worked, we just knew that they removed particles to create great tasting water! 

The primary filtering mechanism for a Brita filter (or any drinking water filter) consists of activated carbon and ion-exchange resin. A sieve rests at the bottom which also serves as a filtration layer. 

+ POOL’s filtration system is similar in that it allows water to sift through a series of materials to remove bacteria and pathogens. Click here to download a diagram of + POOL’s newly patented filtration system. 

Activity: Breaking up the Brita

1. Carefully cut off the top of the brita filter with a utility knife 
2. Observe what’s inside without touching
3. Weigh the cup; record your findings
4. Pour the contents of the opened filter into the cup 
5. Weigh the cup with the filter’s content to determine the amount of activated charcoal used per filter; record your findings
6. Reconstruct the filter and observe how water passes through it

Quiz & Research Questions: 

• How much does the cup weigh? 
• How much does the activated charcoal weigh? 
• How much activated charcoal is used to filter how much water? (Hint: divide the amount of water by the weight of the cup with filtration materials, less the weight of the cup)
• How much water is filtered before the filter should be replaced? (Hint: multiply the amount of water the pitcher holds by the estimated useful life of the filter) 
• What is a sieve?
• What other materials are used for water filtration and how do they function? 

Read more about how activated carbon can remove contaminate from water here.