Subject: Chemistry, Marine Biology, Oceanography
Lesson Topic: Fish Tank Chemistry
Author: Jeff Marshall
Grade Level: 5-12 (detail according to grade level)
Summary of Activity/Lesson: Students observe a fish tank over several weeks changing
parameter and recording data.
Activity:
Fish Tank Chemistry
This long term study addresses a variety of concepts such as:
 Field Experience/Work
 Scientific Method and Experimental Design
 Biology
 Chemistry
 Environmetal Science
 Physical Science
 Oceanography
 Mathematics
Materials:
 Fish tank
 Fish tank air pump
 Fish tank filter
 Stone/Rock for the fish tank
 Live aquatic flora and fauna
 Fish Tank heater
 *Probes OR Chemical Test Kits to measure:
Dissolved Oxygen
Temperature
pH
Ammonium Ion
Nitrate Ion
Salinity
Water Clarity
Biomass
*note: see website for downloadable tools or search for kits available for
purchase and reuse in following years and activities.
*All the tests are not required.
curriculum.
Teachers can select those appropriate to their
Phase 1: Place a fish tank in the classroom to grab student attention at the beginning of
the class period. Fill the tank simply with water and rock/gravel in the bottom. Students
will ask, “Are we getting fish?” Tease them and tell them yes but not until I am sure that
the water is safe.
Using Probe ware (if available) or a chemical analysis kit, demonstrate the tests you
choose from the list above. Instruct students to record them in tables they draw in their
field notebooks (see field notebook lesson plan activity).
Discuss the value of the readings and speculate as to what caused your results.
Also be sure to make sure all the students understand what each test is measuring (i.e.
Why would someone use this test to insure water quality)
Sample Data Table for Fish Tank Chemistry:
Date of
Collection
2/26/05
3/5/05
3/12/05
pH
Temperature(°C)
7.0
6.8
6.7
18
23
25
Dissolved Oxygen
(mg/L)
4.5
4.3
2.5
Environmental
Changes/Description
Undisturbed water from tap
Added 12 hours of light/day
Added air stone/pump
Phase 2: Each week add a non-living parameter to the tank. Allow the parameter to be
in the tank for one week and test again. Students should analyze the data looking for
patterns/trends in order to develop inferences to explain their observations. You can
allow students to bring in “candidates for submersion” or correlate the items you place in
the tank to what you are studying in class. For example, you are studying salinity so you
add salt to the tank. Prior knowledge and current study topics should help them to create
“justified” inferences.
Phase 3: Add living organisms, one kind at a time. For example, one week add plants,
then invertebrates such as snails, then fish, then amphibians. Students should begin to
see that there is a relationship between all the parameters (DO and temp, fish and
ammonium, pH and charcoal filters, DO and air stones).
The great thing about this activity is that it only takes a few minutes a week, but each day
the kids are in your room they see the tank and wonder about the changes that might be
occurring inside.
It is high interest, easy, and can be adapted to many different concepts.
Examples:
 Choose to let the water evaporate naturally and calculate the volume of water lost
each week.
 Measure relative humidity for a parameter as well.
 In an environmental study class, analyze the effects of fertilizers on your
ecosystem.
 If you have the space, run several tanks to compare effects of different levels or
types of factors.
 Ask students to design the perfect ecosystem for a particular plant or animal.
Then create that in your aquarium and determine how perfect it really is.
Because this activity is a precursor to field work that a student may encounter, you may
require the students to have a field notebook to record the changes in the fish tank as well
as other inquiry and observational activities that they undertake in the classroom.
Disclaimer: These lesson plans were compiled, edited, written, and/or prepared by Erin
Spruill, UNCW Coastal Ocean Research and Monitoring Program (CORMP). CORMP is
a NOAA grant funded program, located at the UNCW Center for Marine Science,
Wilmington, NC. Feel free to update or adapt the existing lesson plans to fit your needs.
We ask that you credit the authors and editors of these activities. In addition, please
contact us with new methods and activities you implement in the classroom. Continual
collaboration and revision will allow us to provide educators with the most useful and
current resources for classroom use. Thank you.