How do I use several different Task Templates in the same project?

How do I use several different Task Templates in the same project?

Hi, 

I have created several different tasks templates each with unique fields in the Templates section. I want to use these different task templates in the same project. However, every time I associate any of the templates with my project it changes the template for all my tasks to that one template. I need this because I require the users to input different information for each of the many different tasks in one project.

Any insight helps!

Thank you!