Science Buddies: "Ask an Expert"

Hello. I am working on my science fair project but I dont know how to experiment my hypothesis. My hypothesis is An opened water bottle will grow unhealthy bacteria is by x number of days. What should I do? Please reply quickly

Hi,

This sounds like a great project. Here is a project from the science buddies website that you could adapt to answer your question:

https://www.sciencebuddies.org/science- ... p007.shtml

You can check out the microbiology section of the project guide to learn more about microbiological techniques.

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

What you will probably want to do is measure a bacterial growth curve.

http://www.cellsalive.com/ecoli.htm

Your experimental protocol would involve something like opening bottles of water and doing a total plate count every day for at least 14 days (or as long as possible ) to measure the number of bacteria in the sample. In my experience, bacteria levels can reach up to 100,000 organisms per ml

It will be more difficult to determine if the bacteria are actually unhealthy as that would require identifying them. I think it would be fine to limit the scope of your project to just total number of bacteria.

I hope this will help you get started.

Donna Hardy