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Tuesday 2nd March

Tuesday 2nd March 2021

Good afternoon everyone,

Today in nursery children learnt how to turn dirty water clean. This is a fun science experiment that you might like to try at home. All you have to do is to make your own water filter.

A water filter is a device that removes impurities like dirt, from the water. It’s a sort of super strainer

You will need

  • 2-liter plastic bottle, empty and clean
  • Dirty water (make your own with things like coffee grounds, dirt, crunched-up old leaves, cooking oil, or tiny pieces of fabric)
  • Measuring cup
  • Spoon

As many of the following filter materials as you can get: activated charcoal (available in the fish section at a pet shop), gravel, sand (coarse and / or fine), and cotton balls, pebbles etc.

Coffee filter (an old sock, napkin, or paper towel works too)


 Adult cut the bottle in half. Then flip the bottle's top half over and put it in the bottom, so the top looks like a funnel. You'll build your filter in the top part.

Place the coffee filter (or bandanna, sock, etc.) at the bottom of your filter.

Add cotton balls, charcoal, gravel, sand, and / or other materials in layers. You can use just one of them or all of them. Tip: Think about which order to add them. Bigger filter materials usually catch bigger impurities.

Pour a cup of dirty water into your filter.

Carefully scoop out the filter materials, one layer at a time. What did each layer take out of the water?


 Clean the bottle and try again. Put the filter materials in a different order each time, and time each experiment. What do you discover?

What’s happening?

The slower the water takes to run through the filter the better. The longer it takes for water to move through a filter, the cleaner it gets. Water slips easily through the filter materials, but bigger dirt, gets trapped. The filter materials usually get finer and finer, so they can catch whatever was missed earlier. Activated charcoal can be near the end of the water’s path, because it uses an electrical charge to grab particles too small for us to see.



Your filtered water is not clean enough to drink. But a plant will love it.

The children in nursery really loved their experiments and it’s a fun thing to do at home. Children were also busy writing today and in red class children explored sand and used natural materials to decorate their constructions.

On the blog today

Rina is on the blog today showing you how to plant seeds in recycled containers. Do have a go at growing something, we would love to see the results.

Have a lovely evening.


A homemade water filter using a 2L plastic bottle

Filtering dirty water to make it clean

Exploring natural materials in red class

Emergent writing in first floor class

Rina plants seeds in recycled containers - what can you grow at home?

Still image for this video