Science Buddies: "Ask an Expert"

My name is Connor and this is my first Science Fair. My experiment is to see if water in a creek near my house grows more bacteria in slow moving water or fast moving water. I have an idea of measuring water flow by timing how fast a ping pong ball travels 10 meters. But I'm not sure how to collect the water--should my equipment be sterile? Can I just collect samples in test tubes? I would appreciate any suggestions you could give me. Thank you.

Hi, this project sounds really cool and the ping pong ball part sounds cool. Just make sure you drop it from the same place, and use the same exact ping pong ball to reduce variables.

You most certainly SHOULD use sterile equipment, if you don't use sterile equipment, any bacteria found in equipment will alter your results. You can use test tubes if their sterile.

Here is a guide to how to sterilize, but be very careful because many of the methods use lots of heat

http://www.umsl.edu/~microbes/sterilizing.pdf


Good Luck

Thank you, Adam. My mom can help me sterilize the equipment.

Hi,

Just to add to Adam's advice, you might want to check out Science Buddies' microbiology resources (on this page: https://www.sciencebuddies.org/science- ... ndex.shtml). There's lots of great information about culturing bacteria, etc.

Great idea about the ping-pong ball; I suggest timing the water a few times since there are many variables that might affect your exact results.