This book is a fictional story about a young boy that really wants a dog but needs to prove he's responsible to his parents, so he starts a pet sitting business. But once he's taking care of the fish and the ducks, he puts them in the sun and the water turns green. Through talking to a new friend, keeping a notebook, and doing some investigation, he finds out that the sun combined with the food made algae grow, turning the water green.
This book is awesome. It addresses misconceptions, demonstrates a science notebook, is engaging, and has really great science content, all presented in a package that is familiar to a lot of kids: wanting to prove they're ready for a pet.
I would use this in a life science unit. We would investigate water from a pond or lake in class, looking at it's different colors and looking at it under a microscope. We could then read this book and address the science content of our investigation. ( )