Which Reusable Water Bottle is the Safest?

By:2 period

Alyssa PattonElizabeth Kellogg

Robert Louis Stevenson Middle School

Introduction☻Our question: Which water bottle would

be the safest to reuse?☻Our hypothesis: The Sigg (metal water

bottle) would be the safest water bottle to reuse. We think this because the water bottle can be washed and is stronger than a plastic water bottle.

☻Constant variables: water, temperature.☻Experimental variables: water bottles

Materials♣ 2 plastic water bottles

♣ 2 Sigg water bottles

♣ filtered water ( 200 ml.)

♣ four Petri dishes

♣ Q tips ( amount may vary)

♣ area for experiment (temperature wise)

♣ agar

Procedure

☼ Buy materials ☼ Boil Petri dishes in water to get rid of extra

bacteria☼ fill all water bottles with 200 ml. of filtered water☼ leave bottles in room temperature area for 1

week☼ label Petri dishes☼put in agar☼ Take sample from each water bottle and spread

in Petri dish with a Q tip☼ Record data

Observation Table-1Hour Sigg 1 Sigg 2 Plastic Bottle 1 Plastic Bottle 2

1 2 colonies of bacteria

No colonies of bacteria

5 colonies of bacteria

1 colonies of bacteria

2 7 colonies of bacteria

4 colonies of bacteria

10 colonies of bacteria

7 colonies of bacteria

3 10 colonies of bacteria

7 colonies of bacteria

15 colonies of bacteria

10 colonies of bacteria

Data Graph

02468

10121416

Bacteria colonies

Bottles

Sigg 1

Sigg 2

W.B. 1

W.B. 2

Data Analysis

We compared Sigg water bottles and plastic water bottles. We let the bacteria grow for 1½ hours checking on them every ½ hour. In the end the plastic water bottles had the most bacteria colonies.

Conclusion

Our hypothesis was correct. The plastic water bottles together grew 25 colonies of bacteria. The Sigg water bottles only grew 17 colonies of bacteria. If we were to do this experiment again, we would probably let the bottles sit for a shorter amount of time. This bacteria is most likely harmful. This benefits people because if they found this out, there would probably be less sicknesses and pollution because people would be using reusable water bottles.

Work-Cited • Water bottle picture 3/5/10

http://www.leisureware2you.com• Water bottle picture 3/5/10

http://www.babiestravellite.com• Thank you picture 3/26/10 http://www.photobucket.com • Mythbusters 4/14/10• http://www.youtube.com• Petri dish picture 4/15/10 • http://www.cksinfo.com • Q tips picture 4/15/10• http://www.lotusdonovan.com

Thanks

Thank you to Mrs. Kellogg and Mrs. Barnard.

Thank you Mr. Pham for helping us with our experiment and for being an awesome teacher!!!!!!!!