Vernier Software and Technology
Vernier Software & Technology

Aquarium Monitor


Goldfish are some of the most popular pets, third only to cats and dogs. They live in large tanks of water called aquariums. Unlike humans, goldfish can “breathe” under water. Their respiratory systems have gills, which are thin feathery sheets of tissue that contain blood vessels capable of extracting dissolved oxygen from water.

To keep goldfish healthy, the water quality in their aquariums must be continuously monitored. Water temperature and pH are two important properties to check. Temperature is important because even though goldfish are considered cold-water fish, sudden changes in temperature can shock or kill them. pH is a measure of water's acidity or alkalinity. Water that is neutral has a pH of about 7. Solutions with a pH higher than 7 are considered basic or alkaline and solutions with a pH of less than 7 are said to be acidic. Water that is too alkaline or too acidic can be damaging to a fish's skin and gills.

Design Requirements

Your challenge is to design and build a device that mounts on the side of an aquarium and continuously monitors the temperature and pH of the water. You will incorporate two sensors for making measurements: a Vernier Stainless Steel Temperature Probe and a Vernier pH Sensor.

Your device should periodically take sensor readings and provide an alert if either of the values falls outside of a safe range. It should be clear which sensor reading is out of the safe limits. The water in the aquarium will be considered “safe” if the temperature is between 20ºC and 23ºC (68ºF and 75ºF) and the pH is between pH 6 and 8.

Design and build your device in such a way that all electrical connections remain dry.

Sensors and Equipment

This experiment features the following Vernier sensors and equipment.

Additional Requirements

You will also need NXT Sensor Adapter and a LEGO MINDSTORMS EV3 robotics system.

Vernier Engineering Projects with LEGO® MINDSTORMS® Education EV3

See other experiments from the lab book.

0Introductory Project Robot Walker
1Data Display and Acidity Tester
2Plant Waterer
3Audio Assistant
4String Tension Tester
5Aquarium Monitor
6Cartesian Diver
7Sunscreen Tester
8Battery Tester
9Solar Tracker
10Magnet Detector
13Shell Game

Experiment 5 from Vernier Engineering Projects with LEGO® MINDSTORMS® Education EV3 Lab Book

<i>Vernier Engineering Projects with LEGO<sup>®</sup> MINDSTORMS<sup>®</sup> Education EV3</i> book cover

Included in the Lab Book

Vernier lab books include word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.

Buy the Book

Dev Reference: VST0727

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