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Workshops and Experiences (10-11 years)

A garden on my wall!

Even though we are living in the 21st century, we still have a long way to go when it comes to the construction of buildings that respect the environment.


 The basis of  bioclimatic construction is designing buildings taking the climatic conditions into account and taking advantage of the resources available (sun, vegetation, rain, winds) in order to reduce the impact on the environment and energy consumption too.


Bioconstruction dates back to prehistoric times, when the first human beings lived in caves. However, it is not necessary to go so far back in time. If we look at the houses that were built in villages around the world, we can see that they were built of stone, straw or mud; with more or less doors and windows in different sizes and distributed in different ways, and in different shapes and colours, all depending on the climate, orientation and the resources available.

There are some small examples that we can put into practice, such as green walls that can be set up either inside or outside a building. As well as being a hobby for fans of gardening and design, the interior ones help to lower the temperature and increase humidity, making it a nicer place nicer to be in and breathing is easier.


Have a go at making and looking after your own vertical garden!



  • Botella9 plastic bottles
  • 1 pair of scissorsTijeras
  • 1 strip of woodlistón madera
  • Drawing pinschinchetas
  • 1 rubber hammermartillo
  • Vegetable composttierra
  • Plantsplantas

Caixa ForumVertical Garden. Madrid

Jardín verticalJardin vertical


Let’s get started!Experimento

We are going to make a garden with 9 plastic bottles – 3 rows of 3 bottles -, but you can use more or less bottles depending on how big you want it to be. The first thing you have to do is cut off the base of three bottles. Next, cut a U-shape down to the middle of one side of each bottle, as shown in the diagram. The three bottles should end up as shown here:

botella          botella

Carry on!

Take the other six bottles and make a hole in the base of each one the size of the neck of the bottle without its screw top; then make a bigger oval-shaped hole to put in the plants for your vertical garden.

Keep going, not long to go!

Next, use a sharp object to make a hole in all nine screw tops. Put the strip of wood in place using the drawings pins and the rubber hammer to hang the three bottles upside down.

Put the neck of each one into the base of the following one, and once inside put the top on to keep it in place.

You’re nearly there!

Take the soil and fill the bottles up to the level of the hole. Finally, put some plants into each bottle.

That’s it!

To put up your vertical garden, tie a piece of string to each end of the strip of wood and find somewhere to hang it and enjoy this fantastic hanging garden.



  • Botanic garden: Put in different types of plants and learn more about the world of botany.
  • Urban vegetable garden: Try creating your own vegetable garden at home.
  • Herb garden: If you like tasty food, plant parsley, mint, oregano, etc. Mmmmmmm,!

"A good trick "

Take advantage of rainwater and re-use what is left over

 To collect the water that falls from the lowest bottle in your garden and reuse it to water the plants, take a plastic bottle, cut it in half lengthways, make a hole at each end and tie a piece of string in each one. If you put one of these under each row of bottles in your garden, you will be able to collect the water that is left over and re-use it by pouring it into the top bottle.

Do you want to see how this experiment is done?




 AhorroMake an annual saving of 25% on energy    


                                                                 Eliminate 90% of the pollution in a closed space     


  Retain 90% of rainwater in the first few hours                 


  Reduce physical problems in closed spaces by 50%  

                                                                                      (dry skin and mucus, breathing, fatigue..,)


  Increase the humidity of the environment through the plants’ natural evaporation process


                                      Areas with vegetation produce positive psychological effects  





 Vegetation increases the humidity of the soil because water is retained in its roots, which makes the ground more porous and infiltration is notably higher. Where there are no plants the water is not retained and a phenomenon called erosion is caused as it falls down the hillside dragging all types of sediment with it. These soils are poor and tend to become arid areas with little vegetation. For this reason it is less likely that water will filter and form groundwater in these areas.


did you know

         Sonriente  1m2  of vegetation:

.   generates oxygen for one person for one year

.   traps 130 grams of dust each year

         Sonriente  A green wall the same size as an advertising billboard (16m2):

                       .   filters 10 tonnes of harmful gases annually

                       .   Can trap and process 6 kg of heavy metals

                       .   Reduces noise pollution by up to 10 decibels


(According to studies carried out at the University of Darlington, 2001)


The problem with water: too much or too little


Freshwater is a very valuable resource that is in short supply. Some countries have more freshwater available because of a wetter climate, but there are many places in the world where water is scarce. However, both droughts caused by the lack of water and flooding caused by too much water all at once, are damaging to an environment and those who live in it.





This is a transitory anomaly, which can be more or less prolonged, and is characterised by much less rainfall than usual over a period of time in a certain place





This is when there is water in places that it normally does not occupy. It is often caused naturally by rivers overflowing due to torrential rain or snow and ice thawing following the winter.


 Some factors can increase the risk of droughts and flooding:

* Activities carried out by humans such as over-grazing of livestock, inadequate cultivation methods and unsatisfactory soil conservation techniques.

* Paradoxically, deforestation contributes to both droughts and floods.  

Interesting Websites:

Top ten natural building materials

Guide for Growing Organic Produce

Safeguarding the natural world


Take care of your farm

 Take care of your orchard 

Puzzles on line

 Reconstruct your favorite flower.


Make your own water purifier!

There is an abundant supply of water on our planet, but most of it is saltwater and we can’t use it without treating it in some way. Around four million people, most of them children, don’t even have enough water to drink and wash themselves, which means that a lot of them suffer from serious illnesses. It is estimated that 80% of diseases in developing countries are related to lack of water.

Currently, 10% of the world’s population still does not have access to drinking water , and a lot of work is being carried out to change this so that these people don’t have to drink dirty water which transmits serious diseases such as cholera, hepatitis A, parasitic diseases caused by amoeba or tapeworms, etc. One of the many possible solutions is to treat the water with quality water filtration systems that provide safe drinking water.

Human inventiveness has produced some simple systems that help us to purify rainwater using things we all have around us and which hardly cost anything at all.

Do you want to have a go at making your own homemade water filter?

Passing water through this filter and boiling it for a few minutes afterwards will kill almost all the harmful organisms it may contain. Look and find out how to purify rainwater by passing it through a series of natural filters. Let’s get going!


  • botella1 transparent plastic bottle
  • 1 pair of scissorstijeras
  •  Cotton woolalgodon
  • piedras Stones
  • Ashcenizas
  • Sandarena
  • Charcoal carbón
  • Pieces of gauze gasas


Aguas Texto aguas

Let’s get started!

Carefully cut the base off the bottle and turn it upside down so you can start to put in the materials that will form the filter for our cloudy water. 


Put in the first filters!  

Put in a layer of cotton wool. The more you put in the better the filtering process will be and the water will come out clearer. Then put in a thick layer of stones. They should not be too fine and it is important that they are clean so that they do the best job of treating the water and don’t make it even cloudier. River stones are very suitable, but if you don’t have a river nearby you can use a similar type.

More and more filters!  

Now put in a thick layer of ash and another of sand on top. You don’t need to go to a beach to get it, you can get what you need from any sandpit. The more you put in the better the filtering process will be and the water will come out clearer.

Almost there!

Not much left to do now. Put in a thinner layer of charcoal, which is a great natural absorbent of substances.

And to finish, cover it all with pieces of gauze.

And that’s it!

Take the top off the bottle so that the cloudy water that you pour in through the top part can drain out of the bottom part nice and clear. Put the bottle into a glass to collect the water.



  • Collect rainwater, but not from a puddle or a well.
  • Use a transparent container.
  • Try to make sure that all the materials you use are natural.
  • Try to get them from the vicinity.


And remember!

Filtering the water does not substitute the process of making it drinkable. Although they may look crystal-clear, rivers can contain bacteria that are seriously harmful to our health. 
To make the filtered water drinkable, don’t forget to boil it for a minimum of ten minutes to eliminate all the possible harmful organisms. If you want, you can do this with the solar pasteurizer that we also taught you how to make on this website. Have a go!



Do you want to see how to carry out this experiment?

Earth. The best natural filter we know!!!

Rainwater that falls onto the earth’s surface picks up impurities, clays, plant and animal remains and other types of microorganisms that make it not clean and clear anymore. However, if we take a sample of water from the subsoil, found in the acuifers and underground lakes, we will see that it is much less cloudy.This is due to the filtration of the water through the different layers of the earth’s crust. Depending on the type of rock that the water finds as it makes it way to the earth’s interior, the water will be filtered and purified to a greater or lesser degree.


Permeable and Impermeable Soil

Depending on the type of rock, water will either infiltrate through it or not. There are several types of rocks that make this possible

 a) Compacted or non-porous rocks granito

This type does not allow almost any water to pass through, only through some cracks they may have.  

 b) Compacted Rocks with large fissures caliza

These are usually limestone rocks which have large fissures that the water filters through. These fissures tend to get bigger as the water passes through.

 c) Porous impermeable rocks roca arcilla

These can absorb large quantities of water, but it does not flow through the rock because it is retained inside the pores like a sponge. An example of these is clay.

 d) Porous permeable rocks  Arenas y gravas

Water filters through them easily. They are usually sands gravels and sandstones which are not very compact.


¿Would you like to find out a bit more about aquifers?

 The green layer

manto When it rains, plants and trees retain the water in their roots without letting it descend the hillsides dragging all sorts or rocks with it. When this happens soil loses the small amount of vegetation that it contains, and as a result the diversity of animals too, and therefore it becomes very poor in quality. For this reason it is unlikely that water will filter down to form groundwater in these areas

 Simulating soil erosion


Make a hole in the large bottles so that you can put some soil into one of them, plant remains and tree bark into another, and a piece of turf into the third one, as shown in the photo. Then, take the top half of three small bottles and use string so that they can hang from the top of each of the large bottles. , Pour water into each of the soils you have created and see what colour the water is that comes out of each one. In which one does the water contain less sediment? What are the consequences of the lack of vegetation in soil?



Looking down from space, our planet is just a little blue and white dot. This is because three quarters of the Earth’s surface area is covered by water. This is why it is deep blue with white patches, formed by the clouds. The oceans, seas, glaciers and rivers make up almost all the water that can be seen from space.

Despite the fact that there cuboare large quantities of this resource available, almost all of it is salt water and we can’t drink it, use it to irrigate our fields, or give it to animals.

  Only 2.5% of the water on the planet is drinkable and not everyone has access to it. The rest is salt water. If we could put all the planet’s water into a bucket, only a teaspoon would be drinking water.

 This is why people have been trying desalinate seawater for centuries. Our ancestors made several advances, some more successful than others, but it has been during this century that the desalination process has been perfected. However, there is still a long way to go.



 A simple and efficient system to desalinate water is with a solar distiller. It separates the water from the salt, using the heat of the sun to evaporate the water and condense it on a surface in order to collect it.


  • Bol1 transparent glass bowl
  • 1 glass Vaso
  • WaterVaso
  1. SaltSal
  • Film Transparent film
  • Sticky tapeCinta
  • Piedra 1 marble or small stone

Why does the water evaporate but the salt doesn’t?

Salt is a solid, as is water when it is in the form of ice. For salt to evaporate, it must melt. In order to do this it needs to reach a far higher temperature than water does. Ice melts at 0ºC and salt at 800ºC.

Once in liquid form, water evaporates at 100ºC and salt at 1.400ºC.That is why it is so easy to separate water and salt.


Punto de fusión

Punto de fusión



Let’s get started!

Put the water mixed with the salt into a bowl. Use a tablespoon of table salt for each glass of water. When you have 2cm of salt water in the bowl, put an empty glass in the middle.Desalador

Take care with this part!

Now cover the bowl loosely with transparent film and seal with the sticky tape so that air can’t get in or out.

Next step

Put a marble or small stone on top of the film, just above the glass.

That’s it!

Very carefully, place the bowl in the sunniest spot you can find. The air inside the bowl will start to heat up and after a while you will see how the water inside the bowl starts to evaporate and condense on the film.

Nearly there!

Little by little, the drops of condensed water will start to drip towards the centre of the film and finally fall into the empty glass.

Mission accomplished!

We are desalinating water! If you leave all the water to evaporate, the salt will be left in the bottom of the bowl and the water will be in the glass.



  • Place the bowl in a very sunny place away from draughts
  • Keep in mind that the more sunlight there is, the faster the water will evaporate, and vice versa.
  • Don’t stretch the film too tightly, and allow the stone to sink a little in the centre.
  • Use a transparent bowl and glass so that you can see the whole process.



 A clear example of condensation is when you have a showcondensación duchaer with very hot water. As the temperature of the water is high, it evaporates and is transformed from a liquid state to a gaseous one, and when this steam builds up in the shower and comes into contact with the wall, which is cooler, the contrast causes the vapour to cool down and turn into water again.

  This process of evaporation and condensation carried out with the solar distiller is a mini version of the cycle of the water that is produced in the world.






Although this simple experiment could come in very handy if we got lost in a desert one day, or if we found ourselves adrift in a boat after being shipwrecked, luckily we do not have to fill buckets with seawater in order to desalinate large quantities of water. Nowadays, there are modern plants which desalinate seawater so that millions of people may have drinking water. This is achieved by a process called osmosis, which consists of separating water from salt, and which we are going to try to explain. 



  • Vaso 2 transparent glasses
  • 3 potatoes     Patatas
  • 3 carrotsZanahorias
  • WaterAgua
  •  SaltSal
  • SugarSal

Sol…what? Solution!

A solution is a mixture of two substances , for example water and salt, water and oil, etc. Depending on the amount of each substance used, the solution will be diluted, concentrated or saturated.



The Solute


The solvent


Let’s get started!

Take the two glasses and fill one with tap water and the other with salt water. To make the salt water you will need one tablespoon of salt for each glass of water. 

Be careful with the knife!



Then peel a potato and slice it. Put half the slices in each glass.

What happens?

Immediately we can see that the potatoes that are in the salt water are floating, while the others sink.

Be patient!

Wait for half an hour and have another look. What has happened?

This boat is sinking!patatas hundidas

After half an hour, the potatoes that were floating have sunk to the bottom of the glass. What’s happened? Why aren’t they floating now?

It’s ok…

It is just osmosis, a process by which the potato detects that the water surrounding it is too salty, and so it lets go of some of its own water to balance the water so that it is less salty. The potato dehydrates - loses water and dries out – and so doesn’t float anymore.

Try doing the same with carrots!


  • Keep a potato and a carrot to use as a reference.
  • Experiment with water containing different quantities of salt.
  • Try the experiment with water mixed with sugar to see the transformations undergone by the potatoes and carrots.



Osmosis is the passing of a liquid through a semi-permeable membrane to achieve a balance between the two mixtures. If there is a substance containing a lot of salt on one side of a recipient, and on the other side there is one with less salt and more water, we can place a piece of fabric in between which allows the water, but not the salt, to pass through (semi-permeable membrane). In this way, the water from one side will pass through the fabric to the other side to try to achieve a balance on both sides. That is why one side with lose water, but the other will gain.. 


History of desalination

Although we may think that desalination is something new, it was going round in the minds of many great thinkers thousands of years ago. Thales of Miletus in the 6th Century BC, and Democritus in the 4th century BC, were already saying that fresh water could be obtained by filtering seawater through soil.

As you can see, people have been trying to desalinate seawater for many centuries. In the Middle Ages, several investigators, such as John Gaddesden (1280-1361) wrote about how to do it by various different methods.

During the Modern Age, we began to discover the world. It became necessary to make long sea voyages and large quantities of water were needed to be able to do this. During this period, new advances in desalination systems were made.

In the 19th century, the principles of the so-called “natural” desalination methods were understood. Evaporation, distillation and freezing were the three systems used for desalination and were available to anyone. But it was not until the industrial revolution that it became possible to desalinate great quantities of water. At the end of the 19th century, a gentleman called James Weir designed a system that used the heat given off by a boiler in a factory to heat water and desalinate it.


Do you want to see how a desalinator works?

Interesting websites

 Living and learning with water

Website is dedicated to the joy of water!

Videos to think

  The world water crisis

  Save water or...

Play with water

 Use water wisely

 Fix the pipes to be more efficient

 Make decisions about the use of water

Movies you should not miss

 Top Ten Kids’ Movies With a Green Theme




Pasteurization is a process invented at the end of the 19th century by the French chemist, Louis Pasteur, to reduce the number of bacteria contained in some liquids in order to make them harmless to our health. Pasteur discovered that the hotter a liquid gets the less bacteria it contains. Today, this is a widely-used process and it is known that the microbes and bacteria contained in liquids start to die at a temperature of 56ºC, and it is pasteurized when the temperature rises to 63ºC, meaning that it is free of any bacteria that are harmful to our health.

This is what we are going to do in this experiment, pasteurize water that we collect in a natural way, such as rainwater.


  • Botella1 x litre or 2-litre plastic transparent bottle
  • Lata1 x 33cl aluminium soft drinks can in the darkest colour you can find
  • Caja1 cardboard box or 3 sheets measuring 60x60cm.
  • AluminioAluminium foil or crisp or snack packets
  • PinturaBlack paint and a brush
  • Termómetro1 Thermometer
  • • 1 Pen, scissors and glue





These videos takes you on a trip back through history to see how the discovery of the pasteurizer happened

First part

Second part

Third part

Fourth part

Fifth part

Sixth part

Seventh part


Let’s get going!

The first thing you will need is the transparent plastic bottle. Use the pen to make marks dividing the bottle into three more or less equal parts. Take the scissors and cut off the top third of the bottle. Make a 1.5 cm upward cut in the part you have cut off and then make another identical cut 1cm from the first one. You will end up with a flap that will later help the bottle to fit and close. In total you will need to make four flaps like this one.


Carry on!

Take the drinks can and paint it black. Fill it with water and place it in the lower part of the bottle. Close the bottle by fitting the top and bottom parts together and leaving the flaps on the outside.


Keep going, there’s not much left to do!

Now we need a sheet of cardboard covered in aluminium foil or reflective paper. You need to make a cardboard base with two walls set at right angles.

If you are using a box, cut out two side panels and the top cover. If you have 3 sheets of cardboard, use one as the base and glue the other two together vertically forming a 90º angle.


It’s nearly finished!

Cover this structure with foil or with the reflective side of the crisp packets.


That’s it!

 Turn the structure so that it faces south and put the bottle with the tin inside it in the corner.



  • The can should be as dark as possible so that it heats up as quickly as possible.
  • Make sure the bottle is as tightly-closed as possible so that the least amount of heat is lost from inside.
  • Place the pasteurizer facing south so that it receives as much sunlight as possible.



Do you want to see how this experiment is done?

Nasty pieces of work!

Like everything else all around us, water contains a large quantity of bacteria which in small quantities are inoffensive. However, when many of these bacteria enter our organism, they can make us ill. Therefore, it is advisable that everything we eat or drink is clean and bacteria free.

Enjoy and learn

A fun video to find out what bacteria are

Protect! Don't Infect: Germ Wars

Sing some of the songs about microbes:

"Science Pirates" - Bacteria Song

"Science Pirates" - Wash Your Hands


Squash the bacteria before they get to the plate

Germs in line

Trap the bacteria

Grow big with proteins and knock back the microbes

Get a bit more information

 National Geographic has a lot of information about the world of germs


Build your own ecosystem!

An ecosystem is a unit of natural life made up of a group of organisms (plants, microorganisms, animals) which establish interdependent relationships in a physical environment shared by all: they live there in dynamic equilibrium, feeding themselves from a food chain, exchanging energy and reproducing.

This is exactly what we aim to recreate in this experiment, a small ecosystem in which plants and animals will live in complete harmony. You need to take a lot of care throughout the whole process. Once completed, it will survive all on its own.


  • tarro de cristal1 clean large Glass Jar
  • 1 plastic or glass lid
  • tarro de cristal Very fine sand or gravel
  • tarro de cristal A few small stones
  • tarro de cristal Freshwater plants
  • tarro de cristal Red cherry shrimps (optional)
  • tarro de cristal 1-2 Snails

Red Cherry Shrimp

Gamba Cherry

Red Ramshorn Snail           (Planorbis Corneus)


Let’s get started!

To start, take the clean glass jar and the lid. Fill the jar with 1 – 2cm of fine sand or gravel. Next, put in a few small stones to decorate the bottom of your ecosphere.

Put in the freshwater plant(s) (sagittaria, eleocharis, etc.).

Keep going, it’s nearly done!

Now fill 90% of the jar with water taken from a freshwater pond, river or aquarium.

Finishing touches!

All you need to do now is add some freshwater snails and red cherry shrimps which can be found in any aquarium supplies store.


  • It needs to be in a place with lots of light.
  • Do not place in direct sunlight.
  • Do not place in spots that are either very hot or very cold.
  • Do not open your ecosphere.
  • Try not to move it.

Conservation of the ecosphere

The plants in the ecosystem absorb the carbon dioxide emitted by the animals and transform it into oxygenusing sunlight and chlorophyll, a green substance present in the leaves. They feed on sugars in the water, which are absorbed through the roots, and they breathe in a gas called carbon bioxide. Having done all of this, the plant produces oxygen, which is essential for the survival of any living being. This is the basis of photosynthesis, fundamental for maintaining equilibrium in the ecosphere.

Would you like to see how to do this experiment?

Why is an ecosystem disrupted?

Ecosystems are a set of living beings linked together in a single environment. These living beings live in harmony with the resources that they need. However, when an element which is alien to the environment interferes and disrupts this equilibrium, the ecosystem is put under threat. We are largely responsible for maintaining this equilibrium. Tree-felling, building dams and pouring used cooking oil down the sink are all causes of disruption.

Incredible Ecosystems!

Planet Earth is also known as the blue planet, as 70% of its surface is water, whilst 30% is land. Also, almost all of this is saltwater and constitutes the oceans and seas. The sea hides all sorts of different ecosystems according to its temperature, the amount of light that goes in, the salt content and the animals and plant life that inhabit it. And although it does not seem possible there are living beings that devise ways of living and forming their own ecosystem in the depths of the ocean where there is hardly any sunlight .