Objective:
The student will be able to define filtration, to explain a closed filtration system and to tell why it is an important function in their classroom aquarium. They also will be exposed to the three basic methods of filtration (mechanical, chemical and biological) by watching the classroom aquarium operate.
Materials Needed:
Activity:
Before discussing filtration with respect to the Aquademics™ aquarium, ask students if they know what the word "filter" means (a device for straining out solid particles, impurities, etc. from a liquid or gas). Ask the students if they can think of any types of filters; list their examples on the board. Show students the coffee filter and the air conditioning filter. Get them to comment on the appearance of both filters. Using these household examples, ask students why filters are important in our lives and how they can make our lives better.
Now ask students to speculate on how a filter might be important to a fish. Ask students what types of impurities might exist in their tank that could be harmful or even fatal to their fish. Write their responses on the board.
Define a Closed Filtration System: a system in which water is recirculated through filters and reused. Also, define an Open Filtration System: a system in which water flows into one end of the tank and flows out the other. Ask students which type of system is used in the Aquademics™ tank.
Using the Aquademics™ tank as a working illustration, bring students up to the tank in small groups (or demonstrate to the entire class if small groups are not feasible), show students the filtration device that is attached to the tank. (If students have already completed the Know Your Aquarium lesson plan, they will be familiar with this aquarium part.) Let students watch the water flowing through the filter for a couple of minutes and let them talk about the water as it circulates within the tank. Tell them that the power filter is mechanically removing impure particles from the water, chemically removing toxins through the activated charcoal and biologically breaking down nitrogenous wastes in the nitrogen cycle (cycles will be discussed in another lesson plan).
Also, point out the role that the gravel plays in the biological and mechanical filtration process by helping to trap food particles and wastes.
Result:
Since a filter is the most important piece of equipment in any aquarium, this lesson will give students a basic understanding of the filtration process.
Portions of this page reprinted courtesy of the National Aquarium in Baltimore