Answer:
To improve the reliability of the results, the nutritional component of each category of water must be tested and recorded.
Second, the experiment should be carried out under greenhouse conditions.
The above actions will afford more control. When an experiment is controlled, it means that except for the dependent variable, all other variables are kept constant by the scientist.
By performing the experiment under greenhouse conditions, the kind of water the plants receive, temperature and other biotic actors are kept within measurable limits thus increasing the reliability of the results.
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