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Unit 1. Part (D). Doing an experiment

An experiment is a way of examining a part of a system.

From Hortus Eystettenis a book written in 1613 by Basilius Besler.

The original copy is at the British museum in London, England.

A scientific experiment is a way of finding something out. There are countless experiments that can be made in the world of hydroponics.

In most experiments, something is being examined. Maybe it is a new crop in hydroponics. Sometimes it is a new formula of nutrient that is being tried.

There are experiments going on all over the world. At Africa University there are students comparing tomatoes grown in soil and grown in hydroponics. There are students trying to grow roses hydroponically.

The getting ready for hydroponics in space, there are several universities performing experiments to try to find methods of growing nutritious crops in hydroponic systems.

How do you design an effective scientific experiment?

Rene Des Cartes suggests to divide each of the difficulties under examination into as many parts is possible, and as might be necessary for its adequate solution.

The first step is to find a question you would like to answer. What questions come to mind as you build your hydroponic systems?

When you think of the question, write it down.

Question about hydroponics:




An example question would be

Can you use root nutrient grow carrots in hydroponics?

Once a question is formed, look at how you could answer the question. In the carrot question, this is a possible answer.

Yes, carrots can be grown on root nutrient in hydroponics.

This guess answer is called a hypothesis (high poth o sis).

Your guess answer to your question, or your Hypothesis.



Once you have formed a guess, the next step is to figure out a way to test your answer, or to test your hypothesis.

A way of testing a hypothesis is to design an experiment.

In the carrots hypothesis, a possible experiment is to set up a grower and plant some carrots. It also may help to build a few growers, like four, to check if each grower can grow carrots.

Experiment to test your hypothesis.




The next step is to write down the steps to your experiment, or what you will do to complete the experiment.

For our carrot experiment one way to set up the tasks is

  1. Build four identical growers
  2. Fill each grower with the same type of media
  3. Plant about 20 carrot seeds in each grower
  4. Mix nutrient water with root nutrient
  5. Begin the operation of the growers by pouring nutrient water over each grower every day.
  6. Watch to see if the carrots germinate
  7. Record growth information every day
  8. Grow the carrots to see if they get big enough to eat.

The carrots may take as long as two months to grow to a baby size carrot. This experiment will take a lot of work and a lot of patience.

The steps to complete for your experiment








So you have designed an experiment.

After the experiment has been designed it should be examined for some key questions.

  1. Does your experiment test the hypothesis?


  2. Will the experiment provide the answer to your question?


  3. Is the experiment possible to do?


  4. Do you have the time and resources to do the experiment?


After you have designed the experiment, if time permits and resources are available, and you want to do it, you can go ahead and perform the experiment.

If you do the experiment keep records in your lab notebook so others can follow your work and duplicate the experiment. If you can do drawings or photos to record the plant growth or lack of growth.

Revised: 1 May 2016
Copyright © 2016 Institute of Simplified Hydroponics