Exploring Microbes in Your Fish Tank with the Foldscope Microscope

The activity below was contributed by Holly Stuart during our podcast interview.

This post contains affiliate links — see my disclosure policy.

Microbes are tiny organisms that play crucial roles in our ecosystems, often unseen by the naked eye. They are present in various environments, including aquatic ecosystems. While many students may not have the chance to visit the beach, a lake, or other large bodies of water they can explore the microbial life in a fish tank, providing a hands-on experience that reveals the hidden world of these fascinating organisms.

Studying microbes in a fish tank is accessible and educational. Students can observe different types of microorganisms, understand their behavior, and investigate how they interact with their environment. This activity, whether for a classroom project or a home experiment, opens a window into the microscopic world that sustains life as we know it.

Viewing microbes requires a microscope, which can often be expensive. However, the Foldscope (learn more about Foldscope in this podcast interview and this article) is a paper-based microscope that makes microscopy more affordable. This tool is particularly valuable for educators as it provides high magnification (340x) at a low cost, allowing all students in the classroom to have their own microscope. Using a Foldscope in this activity allows you to discover and observe microbes in a fish tank in a simple, engaging, and educational way.

Materials

• Foldscope or another basic microscope
• Fish tank with aquatic plants
• Small container or petri dish
• Tweezers or small scissors
• Microscope slides and coverslips
• Notebook and pen for observations

Instructions

1. Prepare Your Materials
   • Ensure your Foldscope or microscope is ready for use.
   • Gather all necessary materials listed above.
2. Collect a Sample
   • Use tweezers or small scissors to clip a tiny piece of an aquatic plant from your fish tank.
   • Alternatively, you can collect a small water sample from different layers of the tank (surface, middle, and bottom).
3. Prepare the Slide
   • If using a microscope slide, place the plant piece or a few drops of water on the slide.
   • Carefully place a coverslip over the sample to avoid air bubbles.
4. Observe the Sample
   • Place the slide or sample in your Foldscope or microscope.
   • Adjust the focus until you see the microorganisms clearly.
   • Take note of the different types and numbers of microbes you observe. Look for specific features like cilia, flagella, shapes, and movements.
5. Record Your Observations
   • Use your notebook to sketch the microbes you see and write down their characteristics.
   • Note any interesting behaviors and movements.
6. Introduce Variables (Optional)
   • For a more experimental approach, introduce variables such as:
     • Observing before and after cleaning the fish tank.
     • Comparing samples from different layers of the water column (surface, middle of water column, or bottom gravel layer).
     • Analyzing the microbial life on the live plant versus plastic plant or in the water column.

Wrapping up

Exploring the microbial life in a fish tank provides a glimpse into an otherwise hidden world. By observing and recording the diverse organisms present, you gain a deeper understanding of the complexity and importance of microbes. This activity not only enhances your observational skills but also fosters a greater appreciation for the intricate ecosystems that exist right under our noses. Whether conducted at home or in a classroom, this hands-on exploration is both educational and inspiring, highlighting the remarkable diversity and functionality of microbial life.

Want to learn more about Foldscope?

• Listen in this podcast interview with Holly Stuart, the Education Specialist for Foldscope Instruments, and this article based on our interview.
• Looking for another Foldscope activity? Try this one out!
• Foldscope’s website
• Read Foldscope’s story
• Get an individual Foldscope 2.0 (with 340x magnification to view bacteria!)
• Explore Foldscope classroom kits (20 Foldscopes or 100 Foldscopes)