Science Buddies: "Ask an Expert"

Will my project be a winning one If I base it on an already conducted one. https://www.sciencebuddies.org/science- ... background
I had a similar idea as the one in the url but now I can't do it because it has already been done. Therefore, I want use different types of water or different types of plants, but I want to test to which ph is suitable for different plants. How should I conduct this? Is this a good idea?

Hi Lulama

Welcome to Science Buddies!

Thanks for including the link with the project you are interested in. You can certainly do an original, winning project on the subject of greywater. The projects on the Science Buddies websites provide excellent background information and an outline for a well-controlled experiment. For a winning project, you will need to do at least one experiment that will answer an original question.

Your idea of investigating pH is a good idea. The greywater will have a specific pH when it is generated. How would you adjust the pH? Why would the pH of the greywater make a difference in the specific experiment you are doing?

Since you are just getting started, I recommend that you do additional background reading on the subject of using greywater and find out what kinds of problems are associated with using greywater. Try to find articles from the scientific literature on your topic. You could develop your idea of testing pH, or perhaps you could answer one of the following questions.

1. What is the best way to store greywater and transport it to the site where it will be used? (this would be an engineering project).
2. What is the best kind of plant to grow with greywater?
3. What contaminant in greywater inhibits the growth of the plant you are testing?
4. Is there an easy way to remove plant-inhibiting compounds from greywater?
5. What is the best detergent to use for laundry if the water will be used for growing African Violets (or other flower) ?
6. What is the best way to store greywater if it will not be used for more than 24 hours?
7. Is it possible to make greywater safe for growing food plants?

If you do more reading on the topic, you should be able to think of other ideas, or perhaps adapt one of these ideas for your poject. All you need for a winning project is one well-controlled experiment with measurable results that will answer your project question. It's always best to repeat the experiment to confirm your results.

Here is the project guide from this website; start from the beginning and follow all of the steps:

https://www.sciencebuddies.org/science- ... ndex.shtml

Good luck. Do let us know if you have any questions.


Donna Hardy

Thank you for the response

I have figured out the idea for my project. I will have four samples of water: three types of grey water, and normal tap water as my control.

The grey water will be directly taken from washing bath. I will then separate it into three samples. They will all be tested for pH balance, then the first one will be left untreated, the second will be treated to be alkaline by directly added organic compost and the third will be made acidic by addition of lime.

I have 28 radish seedlings of which will be divided into groups of four: the control, and the three experimental in order to determine a reliable average.

I then will measure my results in terms of pH of the soil water after the gray water has been applied, I will measure the length and number of leaves on the plants.

My question therefore is is my method in conducting my experiment reliable? Or are there certain factors missing?

Hi Lulama ,

Your experimental plan is a good one and will provide you with quantitative data for a complete science fair project. I do have some additional comments and suggestions that you might consider, if you have time.

Your project is basically an investigation to determine the best conditions to use grey water. You are testing the effect of adding organic compost or lime on the growth of radish seedlings, assuming that the pH will affect the growth of the plants. Can you answer the following questions?

1. What is the optimum pH for radish seedlings? Have you done a preliminary test to see what the pH of the grey bathwater will be? Do you really need to adjust the pH?

2. If you do need to adjust the pH, adding organic compost will add a complex mixture of components that might do more than change the pH. If you want to adjust the pH, I recommend using a simple acid or base to shift the pH. The problem is that if the organic compost results in the best radish seedling growth, you won't know if the reason is the pH or some unknown component in the compost.

3. Lime is calcium carbonate, a basic substance, which will raise the pH. What is the natural pH of your tap water? If it's already alkaline, then you probably don't need to add lime. If it's acidic, then adding lime might help.

4. How will you be measuring pH of your samples? If you are going to do a project on pH, you will need to understand and explain pH to the science fair judges. Please ask more questions if you need more information on this topic.

5. What about the soap? If seems to me that the primary concern about using grey water to grow plants is the components that might be found in bath water. This might be soap, shampoo, cream rinse, or extra bacteria. Can you use your project to investigate how to eliminate any toxicity in the grey water? You need to identify the substances found the in the grey water you are using.

6. What have other researchers found about using grey water? Did you read background articles on this topic to find out what has been done before.? Is this why you decided to investigate the effect of pH? Progress in science is made by finding out what everyone has done before, and then doing a new experiment that will answer the next question.

7. Once you finalize the details of your experimental groups, you need to make sure that all other parameters will be carefully controlled. It will be best to measure temperature, ensure the light is the same for all plants, and measure the water used to keep the plants growing. What soil will you be using? Will you be adding fertilizer to the plants? Will you have enough grey water to water the radish seedlings throughout the experiment? Is using tap water the best control to use? Are the conditions you will be using optimum for radish growth?

If you start with seedlings, you will need to measure the difference in growth from day 1 to the end of the experiment. The important point is that only the water will be different for each group of radishes.

8. Do you have time to repeat the experiment? Science fair judges are always impressed with duplicate results.

9. Do you already have your radish seedlings? If so, then proceed as planned. If not, then it would be better to have a few more plants in each group, although using 4 plants in each group is vastly superior compared to using just one plant.

I hope this helps. Let me know if you have any questions.


Donna

Hi,

Here are some more things to think about.

What is your project question and what is your hypothesis? Here is the project guide from this website:

https://www.sciencebuddies.org/science- ... ndex.shtml

Here are the optimum conditions for growing radishes. The optimum pH for radishes is 6 to 6.5. Other than the water, which is your independent variable, will you providing optimum conditions for your radishes?

https://www.botanicalinterests.com/arti ... est-Radish

Measuring plant growth. Measuring radish growth is challenging because they don't grow tall. It sounds like you will be measuring plant height and number of leaves. Will you be able to continue the experiment until radishes form? It would be interesting to harvest and weigh the radishes at the end of the experiment. Be sure to take photographs, so anyone who reads your project will be able to see what happened.

Here is a commercial website that sells materials that can be used to recyle greywater. While this type of site is usually not the best source for background information for science fair projects, this site seems to do a good job of describing problems in reusing greywater. Does your project help solve any of the known problems?

http://oasisdesign.net/greywater/misinfo/

Here is a scientific report on greywater use, including references. This would be excellent to include in your bibliography, and you can use the content for inspiration for your project. Can you find any more scientific references?

http://pacinst.org/app/uploads/2013/02/ ... rview3.pdf

It might be useful to define the composition of your bath water. This would be helpful in reproducing results. Instead of using a random batch of bath water, choose one item that might be in the water, such as shampoo or bath soap and add a measured amount of theproduct to water. You should use a quantity that would be typically used.

Please let me know if you have questions or comments.

Donna

Hi Donna

I have the science project, based on improving the pH of grey water that is to be used on plants specifically vegetables. I will be using 3 groups of 30 spinach plants of which will be group A,B and C. A will test for normal water, B will be laundry water and C will be laundry water with white vinegar or an alternative acid medium. I want to Base this project on spinach which is a vegetable, is the laundry water mixed with vinegar too harmful on it it of it being edible?

I also want to grow my plants outside in the garden but I don't want factors such as rain or wind to influence my results are there any ideas on how or what I can construct to prevent this?

I also want to send a sample of the laundry water to a local water plant where they can trace the exact compounds in normal tap water and laundry water.

I have been given three weeks to conduct this experiment will I be able to obtain sufficient results?
Thank you
Lulama

Hi Donna

I have the science project, based on improving the pH of grey water that is to be used on plants specifically vegetables. I will be using 3 groups of 30 spinach plants of which will be group A,B and C. A will test for normal water, B will be laundry water and C will be laundry with white vinegar or an alternative acid medium. I want to Base this project on spinach which is a vegetable, is the laundry water mixed with vinegar too harmful on it it of it being edible?

I also want to grow my plants outside in the garden but I don't want factors such as rain or wind to influence my results are there any ideas on how or what I can construct to prevent this?

I also want to send a sample of the laundry water to a local water plant where they can trace the exact compounds in normal tap water and laundry water.

I have been given three weeks to conduct this experiment will I be able to obtain sufficient results?
Thank you
Lulama

Hi Lulama,

Welcome back. I'm glad you are continuing with this project. I do have some suggestions that will help ensure your success.

1. Don't use unknown laundry water and plan to send it out for analysis. I doubt you would be able to obtain the results you need. Just pick one laundry detergent that you can find ingredients listed for and make a solution with water. This will eliminate a lot of unknowns.

2. I assume you are adding vinegar to neutralize the high pH of the laundry detergent. Plants have an optimum pH of about 6.5 to 7, so if you could measure the pH of the detergent solution and add just enough to neutralize the solution, it would probably work well. If you can't measure pH, then add just a small amount, maybe 3-4 concentrations of vinegar plus one sample with no vinegar. You will also need a positive control with no detergent.

3. What happened to the radish seeds? Spinach plants will work, but these plants do grow more slowly that radishes. You should be able to get results within 3 weeks.

If you don't have indoor grow lights, I think you will get better plant growth if you keep the plants outside. If you keep all of the plants together, they will get the same light, wind, and other conditions, so conditions should be controlled. You need to have as much plant growth as possible so you can measure the difference between laundry detergent and the control.

4. Greywater is not recommend for use in growing plants used for food because of the concern about unknown microorganisms. If you already have the spinach plants, do proceed with the project so you will get some results. However, if the science fair judges as you about this, please do explain that you know not to use greywater on food plants.

Let me know if you have other questions.


Donna

Hi,

Here's a little more information that should help you:

Spinach plants have an optimum pH of between 6.5 and 7.5 and they grow best outdoors in full sun.

http://www.gardening.cornell.edu/homega ... e4c19.html

Laundry detergents have a pH between 7 and 10, so the vinegar would help plant growth only if the concentration will shift the pH into the range that is optimum for spinach growth.

https://www.reference.com/science/ph-le ... e6b82eb34f

Donna