Hydroponics for Kids – The Ultimate Parent Guide

Here’s a great way to garden with a difference and teach lots of science in a fun way by learning all about hydroponics for kids!

Toddlers and small children might enjoy the harvest from this indoor garden for kids but it is definitely an activity for older children. 

hydroponics for kids

Explaining Hydroponics – What is Hydroponics? 

Unlike organic or traditional gardening with children where the emphasis is on creating strong effective root systems, hydroponics is the process of growing plants by providing all their food and nutrients through their water. 

This can be achieved in a small area like a rooftop or even in your own home. 

Plants need certain things to grow and keep healthy. They need light, oxygen, nutrients and support for their roots. 

Usually, all of these come from the soil in which they are planted but in hydroponic systems, the nutrients are carried through the water to their roots. Plants don’t mind, though as long as the following processes are in place 

  • A place to grow
  • Sunlight or artificial grow lights
  • Water
  • Plant food

In traditional gardening, plants spend a long time sending out lots of roots to collect nutrients for their growth. In hydroponic gardening, plants get their food easily and so they can grow quickly and produce fruit and flowers in a short time. 

hydroponics at home

Types of Hydroponic Systems 

There are two main types of hydroponic systems.

Passive Hydroponic Systems

This will be the easiest system to practise with and if your kids love it you can upgrade to an Active System.


A Passive System in a Coke bottle

  1. Collect Supplies – a 2 litre Cola bottle, an old cotton sock, scissors, bowl, cling film, Peat moss, Perlite and bean seeds. 
  2. Cut your Coke bottle in 2 equal parts.
  3. Create your wick by inserting the cotton sock tightly through the neck of the bottle, long enough to hang into the water reservoir. 
  4. Mix one part Peat Moss and one part Perlite. Add the nutrient mix as per the manufacturer’s instructions.
  5. The nutrient mix could be added to the water instead depending on the type of nutrients. 
  6. Fill the bottom half of the coke bottle with water. 
  7. Put the neck of the bottle over the water reservoir with the sock extending about an inch (2.5 cm) into the water.
  8. Fill the top of your bottle with the growing medium. Make sure that the wick is snug so no soil falls through into the water 
  9. Water the growing medium lightly. 
  10. Plant your seeds about double the diameter of the seed. 
  11. Cover the top of your bottle with cling wrap and keep in a warm dark place. 
  12. When the seeds germinate you can uncover them, move them into natural light and let them grow tall. 
  13. Keep the water topped up so the wick does not dry out. 

Active Hydroponic Systems

An Active System requires a pump (like a pump for a fish tank), to pump the nutrient-rich water into the medium. This is usually set to happen once or twice a day. The pump also aerates the water which gives the roots oxygen. 

indoor gardening for kids

Media or Water? 

It’s simpler to grow in a medium like Peat Moss and Perlite but you can grow plants in nutrient-rich water with just a wire mesh to stop the plants from drowning because most plants can’t swim! 

Do Plants Eat? 

Plants need nutrients which they usually find in the soil. These nutrients help the plant to use the sugars that it needs to make its real food through photosynthesis. (You can see where the science comes in!) 

Hydroponic nutrients are in liquid and water which bathes the roots but the effect is just the same. 

Tap water has a lot of chlorine so try to use distilled water if your plants look a bit unhappy. 

Don’t let too much water evaporate either as over concentrated nutrients might make your plants very unhappy. 

Nutrient pH – More science!

Measure the pH level of the nutrients in your medium or water. You have to buy special strips or a pH measurement tool for that. Plants absorb nutrients best in a slightly acidic situation – round about pH 6. 


Plants need oxygen around their roots. Oxygen is found in tiny spaces around soil particles. Plants use oxygen to trigger the release of the energy made during photosynthesis. 

In your Coke bottle garden, you can use Kid power with simple straw aeration. Just blow into your water with a straw for a few minutes 2 or 3 times a day. 

In an active system, a pump will oxygenate the water. 

Rockwool, added to the growing medium, has a great capacity for holding oxygen. 

Choices, choices, choices? 

Hydroponics for kids could be just a fun project with a coke bottle. 

BUT it could become a large and impressive active system which feeds veggies to the whole family. 

It could even become the start of a multi-million dollar business supplying chillies or strawberries or lettuce to the Nation. 

When you start a project, like hydroponics for kids, you are teaching a skill and you are learning some science but you could be training entrepreneurs for the future.