Thank you for the information! I will get some SafeStart in the morning and will take a look at the Tetra Whisper (I was a little worried about the water falling - since the water line will be a few inches under the tank height. I will ask the teacher what kind of water she used. Great teachers, but the information they have had to date was pretty simplistic on the other items - i.e. they were not sure about a lot of things.