STEM Water Projects and Science Experiments For Kids

50+ STEM Water Science Experiments and STEM Projects for Kids in Elementary – play, educate and grow with nature’s favourite drink

Water is one of the greatest mediums for exploring science. It’s easy to work with, it’s readily available, it’s safe and kids love playing with it. It is impossible not to have fun while learning with water. Are you looking for some great ideas for water projects in your class, homeschool or home? Find inspiration on this list of over 50 fun science experiments and water projects for kids!

The Best Water Science Experiments for Kids

Water projects and Science Experiments

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To make navigating this resource easier, I have divided all of our water projects and STEM activities into some general categories.


Bath Bombs or Bath Fizzies are the ultimate in bath time fun! They are also an exceptional chemistry experiment. You can simply make a bath bomb and see how water is the magic ingredient to trigger the reaction, or do a science experiment exploring the effect of water temperature on bath bomb reactions.

Bath Bomb Science Fair Project

Water Lab Exploring Safe Drinking Water is a science experiment that turns students into water testers with an eye for safety. Using water sources around your home or school you can easily set up this activity and in the process learn a valuable lesson about how precious safe water is for families everywhere. For more testing ideas you can check out this article.

Water STEM Lab - An activity for kids exploring what makes water safe with hands on exploration and discovery. A great STEM and safe drinking water lesson.

What’s the difference between baking soda and baking powder? Learn the answer in this experiment. Take water and add sodium bicarbonate or baking powder. Watch the results to see something spectacular!

What's the difference between baking powder and baking soda? Find out in this epic science experiment of eruptions!

Super Simple Chemistry is a kid favourite activity that explores how different substances mix with water. Not everything dissolves, start exploring these ideas with this simple activity.

Super Simple Chemistry Kids Love - For the home, classroom, camp or troop, this fun chemistry kids activity is educational, messy, fun!

Learn about pH (acidic and basic) properties with this fun fluids experiment that uses items from your kitchen to create a fascinating lab study.

Using items from the kitchen this fascinating experiment explores Acids and Bases and pH Levels. Kids will love digging through the pantry to test out whether items are an acid or a base, and explore pH levels of every day items. An excellent elementary experiment for hands on with science with lots of further studies.

Elephant Toothpaste might not seem like a water science experiment at first, but this activity is actually really cool because one of the by products of the chemical reaction is water!

Elephant Toothpaste


Skittles Experiments require only two things – Skittles and Water. It may be simple, but this is one water experiment that is stunningly gorgeous and will have kids begging for more science time! With our study we brought in Vincent van Gogh’s Starry Night as a way to see fluid dynamics in action.

Skittles Experiment for the Science Fair inspired by Starry Night

The classic oil and water experiment is a fascinating way to introduce students the density, and in this experiment the results are beautiful!

oil and water experiment

Marble Run Density Project is a simple activity that explores the density of different liquids using marbles. It’s fun and accessible for all ages. Everyone loves a good race!

Simple Science: Exploring Denisty with Marble Races. A great way to see the effect of liquid density with stuff you have in your house right now.

Does It Float – Pop Can edition is a fascinating activity that demonstrates how the density of different canned drinks affects whether they float or not. The results are fun and this makes for a great activity during camp outs.

Do soda pop cans float or sink? The answer is a fun outdoor, camping STEM activity that is sure to wow!

Teaching The Scientific Process With Water Balloons – This is a fantastic idea for learning how to create scientific proof by exploring the science behind the “does it float pop can edition” experiment.

With this activity we are teaching the scientific process and encouraging kids to use inquiry based activities to prove theories.


Chromatography Flowers is a super easy activity that even little kids will be able to do with minimal adult help. Watch how water helps colours travel through the coffee filter making pretty designs. For older kids, take the challenge up a level and light up your flowers with a simple circuit building activity.

With the popularity of our Circuit Bugs STEM Activity it was time to come up with something new, something with a little extra art. Introducing Circuit Flowers! Explore chromatography, diffusion, engineering and circuit building with this hands on STEAM activity. Great for mothers' day, spring, girls in STEM, and more!

Walking Rainbow – This was our attempt at the walking rainbow experiment but when things went wrong it became a whole new and exciting water science lesson.

The Walking Rainbow science experiment should have been easy, but due to a mistake we discovered a fascinating capillary action and natural balance project.


It’s time to get chilly with this mind bending experiment. In Snow and Ice Simple Science – Melting Magic we ask kids to predict the outcome of a test that will have them saying WOW! when they see the outcome.

Snow Ice Simple Science is an experiment all ages can do and teaches valuable lessons about the molecular structure of water in ice form versus snowflake.

Why does salt melt ice? This STEM activity dives into some great winter science as it explores how salt affects ice.

A fascinating Winter STEM Activity for elementary kids exploring the effect of salt on ice. Significant results provide rewarding STEM hands-on learning.

Live somewhere cold? Explore the Mpemba Effect in a spectacular way as you create snow.

How to Make Snow and explore a cool property of water called the Mpemba Effect. It uses a little bit of science, a little bit of hot water, and a whole lot of cold to make this spectacular snow storm happen like magic.

Bottle Crush is a project that will have kids asking to go outside on a cold winter day over and over again. Like magic, kids will learn how to crush a plastic bottle without touching it, astounding their friends and family.

Bottle Crush - Crush a bottle with your mind, and a little science. Inspired by Mythbusters, a science experiment that seems like magic!

Ice Fishing Science Experiment – What is more winter than Ice Fishing? In this fun, hands on science, kids learn how salt and water interact as they go fishing for the big catch! A great challenge for a classroom or summer camp.

Ice fishing science experiment


Slurpee Science Continue exploring the power of salt and water with states of matter changes with this experiment that ends with a tasty treat.

Sweet slurpee science is a fantastic activity for kids, with a tasty result they will love. This simple heat transfer experiment is perfect for all ages.

Layered Lollipops is a fascinating study into density. Makes a beautiful experiment that smells amazing!

Layered Lollipops uses candy in a beautiful candy stem challenge

Lego Gummy Mummies is a project that explores what happens when water is removed, also known as desiccation which is part of the mummification process. It’s also an experiment using candy minifigs, so kids love it!

Lego Gummy Mummies are a unique experiment exploring desiccation. An excellent activity linking science and ancient historical cultures like the Egyptians.


Build A Water Clock and learn a bit about history with this easy STEM project. This project can be scaled for use by kids of all ages.

Water Clock STEM Activity

Ice STEM Projects explore all the amazing things you can do when water enters a solid state, better known as ice! The dinosaur ice sculpture is just too cute and kids will love engineering their own ice creations.

An Ice STEM Engineering Challenge that is fascinating and an inspiring learning opportunity. Perfect for homeschoolers and young scientists, with everything you need in one box.

Build a Compass and embrace your inner Einstein! Witness the invisible forces that captured a young Einstein’s imagination and led to a lifetime of incredible discoveries.

DIY compass

Build a Heart Model filled with water (aka blood) and explore how the blood moves around the heart.

This Heart STEM activity to build a functioning heart model uses all 4 STEM pillars - Science, Technology, Engineering and Math. Kids will spend some time learning about their own heart rates, then how blood flows through the body. For the exciting conclusion engineer and build a functioning model of a beating heart.

Engineer An Ice Lantern, perfect for the holidays.

Engineering A Christmas Ice Lantern - Holiday STEM activity


Chasing Hearts – This science experiment is like magic as you explore science and physics principles, all while playing a fun game!

Chasing Hearts Valentine's Game is a fun challenge that has a science twist. Students will love watching the "magic" as their hearts lift and start to drift away. But using a little physics you can capture your hearts.

Keep it Dry – A slight of hand activity that kids of all ages love to take a turn at. Become a magical scientist!

Can you keep paper dry in water, even when it's completely submerged? You can if you understand the science in this magic meets science water project.

Why Does Water Rise? is an activity that is like magic! Kids love this STEM Activity that involves a little tech in the investigative process.

Why Does Water Rise? Best Science Experiments for Kids!

Build a Leak Proof Bag that is filled with water and pierced through with tons of pencils? Sounds impossible, but it’s not if you know the science!


Students get hands on with a major threat to our marine environments in this Oil Spill Cleanup Experiment.

Oil spill cleanup experiment for home or classroom

Learn about the Water Cycle in this simple science experiment in a jar. Perfect for students or as a classroom demonstration.

Water Cycle for Kids

In this experiment, explore how acid rain affects plant life. It is a simple experiment with powerful results.

Acid Rain Science Experiment

Next, we explore how water pollution affects plants. This is a simple experiment exploring the effects of water pollution in two different ways. Students learn about osmosis, pH and the scientific method.

A simple science experiment exploring the effects and damage caused by water pollution on flowers

The Water Desalinization Project is a interesting activity that explores how to remove the salt from salt water making it safe to drink.

A series of experiments exploring the properties of saltwater including a desalination science experiment (the removal of salt from saltwater).

This Fish Diving Activity is a neat way to explore how fish use air to help them move around underwater. A similar activity involves creating a Cartesian Diver.


DIY Play Dough Bubble Bath is not a water project exactly, but it’s an inexpensive way to create some bubble bath play dough. Perfect for doing water projects with kids in the bath tub or at a water table.

DIY Play Dough Bubble Bath - Easy clean fun!

Oobleck is a captivating activity to explore the difference in liquids. With the addition of one ingredient to water you create the most bizarre substance. Oobleck projects are an excellent addition to the study of states of matter and the senses. We LOVE playing with Oobleck and have created dozens of fun ways to explore this non-Newtonian Fluid.

Oobleck Sensory Science

DIY Soap Projects, especially Soap Jellies are a fantastic sensory experience that will encourage kids to get clean! They are so much fun, and super easy to make. For an incredible cross study, make our DIY Layers of the Ocean soap and learn about the ocean with this gorgeous and easy soap making project.

Jelly Soap Making - Sparkly, Jiggly, Soapy Fun Jellies!
Layers of the Ocean Soap project for kids

More Water Science Experiments

Explore why the Sky Changes Colour in this fascinating and simple science project demonstrating how the skies change colour during sunrise and sunset.

Sky Science is a simple experiment that answers one of childhoods biggest questions - Why is the sky blue and why does the sky change colors at sunset?

Another great project is the Rainbow Rain Project. Students will create a stunning display of colour in a jar to explore how clouds (made with shaving cream), hold and release moisture, creating rain! This project is GORGEOUS and so simple.

Rainbow Rain Shaving Cream Cloud in a Jar Experiment

Magic Glitter is a cool experiment that is also a powerful demonstration on how soap works and why it is so important to wash your hands with soap.

Magic Glitter Handwashing Demonstration

Have fun learning with nature’s most valuable liquid – water!