I have a science fair question and thought this would be the best place to ask a chemistry question. My sons topic (given to him, not selected) is on the food chain. We looked and looked on the net and about the best we could come up with was acid rain. We're going to test the effects of acid rain on plant growth. We're about a week late starting so I need to just get close on pH instead of saying it's exactly X. Lemon juice has a pH of 2-3. If we go 1 part lemon juice and 1 part distilled water, will the pH be in the 4.5 to 5 range? If so, that's close to acid rain. We could do two with pure lemon juice, two with a mix, and two with distilled water. Sooo, any thoughts on mixing the water and lemon without the aid of pH strips?