Use the nutrient solution shown in the tables or a solution prepared from commercial pre-mixed nutrients. Adjust the pH of the solution to between 5.5 and 6.5.
Pour the solution into three containers. Do not change the pH of the solution in the first container. This solution is the "check" or "control." Lower the pH of the solution in the second container to below 4.0 by adding dilute sulfuric acid. Raise the pH of the solution in the third container to 8.0 or above by adding a dilute sodium hydroxide (NaOH) solution. Test the pH of the solutions with an indicator.
The following plants do well at a pH range between 5.5 and 7.0; carrot, coleus, cucumber, geranium, orange, pepper, petunia, strawberry, turnip, and violet. Grow a plant from this list in each of the three solutions. Choose only one kind of plant (pepper, for example), and be sure the plants are about the same size. If you use seeds, plant them all at the same time.
Notice the differences in growth between the plants in the three solutions. You may want to set up various pH ranges to find the best pH in which to grow a particular plant.
Experiment 1: pH Levels.
2:38 AM
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