Form a hypothesis to prove or disprove. The hypothesis should be a summary of what you expect to happen over the course of the project. For example, here is a sample hypothesis for this type of project: "The plant that uses the water with the highest pH balance will grow to be the biggest."
Plant seeds in identical pots with the same potting soil, if using seeds for your project.
Label each plant "1," "3," and "7." These numbers will help to keep track of the plants and also to serve as a reminder of which pH water they will get.
Use your pH strips and add lemon juice to distilled water until you have three different containers of water with pH 1, 3, and 7 respectively.
Add an identical amount of water to each plant from their respective water containers. Be sure to record how much water you are adding to each plant each time and keep this number constant.
Observe your plants over a set period of time, and take pictures at each time point. For example, if you are doing the project for 1 month, you could take pictures of each plant at the end of each week.
Write conclusions about the effect of acidity on plants by summarizing the differences in the plant's height, flowers, and leaves.
Create a display using posterboard or cardboard to show the steps in your process, your hypothesis, pictures of the experiment and the results of the project. You can also choose to bring the plants with you and display them next to the posterboard. Be sure that your display walks the observer through the steps of your project and describes it in clear and concise language by using pictures and text. Ideally, your presentation should explain itself without you needing to say a word.