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Comparing different types of aquarium water filtersFeatured science projectScience project video


The materials required for this science fair project:
- 6 gold fish
- 2 fish aquariums
- Fish food
- Enough water to fill the aquariums
- 1 sponge filtration system
- 1 under gravel filtration system
- 1 freshwater test kit


1. For this science fair project, the independent variable is the type of filtration system used – sponge filtration or under-gravel filtration. The dependent variable is the pH reading and the ammonia content of the water in the aquarium. This is determined by using a freshwater test kit . The constants (control variables) are the number of fishes in each tank, the types of fish used and their age/maturity, the size of the tank and the amount of fish food given daily.

2. The fish tanks are prepared by setting up the sponge filtration system and the under gravel filtration system in each of the aquariums. The aquariums are then filled with fresh water and the filtration systems are powered up . Three gold fishes are placed inside each aquarium.

3. Using the fresh water test kit, the pH readings of the water and the ammonia content of the water are taken. The readings are recorded .

4. The fishes are fed once a day with  equal amounts of food in each tank. For the next 4 weeks, the water in the tank and the filters will not be changed.

5. Once every week, for the next 4 weeks, the levels of ammonia and the pH  of the water in the aquarium  are measured using the freshwater test kit..

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Complexity level:
Project cost ($):
Time required:
1 day to prepare, 28 days for the science project experiment
Material availability:
Easily found
Safety concerns:

Basic safety requirements