Science Buddies: "Ask an Expert"

I am growing algae (Chlamydomonas) for part of my science fair project. It is not visible in any of the tests I am currently experimenting on. The algae is growing in soil-water medium several petri dishes. They are getting the right amount of light supplied by fluorescent bulbs and the temperature in the room that they are growing in is a fluctuating 15 degrees Celsius. I am wondering about how many days do you think it would take for the algae to become visible in my tests?
-Trebleclef1029

It may take a few weeks depending on the conditions, as many as 30 days according to http://www.scienceproject.com/projects/ ... /IB033.asp
Be careful while working with Algae and Good luck!