Aquarium Monitor Project

Introduction

Goldfish are some of the most popular pets, third only to cats and dogs. They live in a large tank of water, called an aquarium. Fish are able to “breathe” underwater, because their gills extract dissolved oxygen from water. To keep goldfish healthy, their aquarium must be continuously monitored. The temperature of the water is one of the most important properties, because even though goldfish are considered coldwater fish, sudden changes in temperature can shock or even kill them. The alkalinity or hardness of the water is also important. Goldfish produce a large amount of waste after eating, which releases harmful chemicals into the water. Fish owners can reduce the alkalinity of aquarium water with additives.

In this project, your challenge is to build a sensor-controlled robot to monitor the water in an aquarium. Your robot should periodically measure the temperature and alkalinity values, and store the data in a file. You will use a Vernier Stainless Steel Temperature Probe to measure temperature and a Vernier pH Sensor to measure alkalinity. The water in the aquarium will be considered “healthy” if the temperature is between 20–23°C (68–75°F) and the alkalinity is between pH 6–8.

Objectives

In this project, you will

• Build a robotic device to monitor an aquarium.
• Use the NXT to determine the pH and temperature of the water in an aquarium.
• Write sensor data to a text file.