Which Reusable Water
Bottle is the Safest?
By:
2 period
Alyssa Patton
Elizabeth 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-1
Hour
Sigg 1
Sigg 2
Plastic Bottle 1
Plastic Bottle 2
1
2 colonies
of
bacteria
7 colonies
of
bacteria
No
colonies of
bacteria
4 colonies
of bacteria
5 colonies
of bacteria
1 colonies
of bacteria
10
colonies
of
bacteria
7 colonies 15 colonies 10
of bacteria of bacteria colonies of
bacteria
2
3
10 colonies 7 colonies
of bacteria of bacteria
Data Graph
16
14
12
10
Bacteria
8
colonies
6
4
2
0
Sigg 1
Sigg 2
W.B. 1
W.B. 2
Bottles
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!!!!!!!!