"What a neat unit! It's easy to set up, easy to run and make work the first time. It does a number of nifty hands-on demonstrations and experiments, illustrating a variety of natural phenomena. The instructions are straight-forward, and the observations/experiments are well thought-out. I highly recommend it."

Dr. William S. Cordua
Geology Department
University of Wisconsin at River Falls

"As a student who has taken practically all the science classes offered in my high school, the Density Flow Model is the best source of demos I've seen -- it's probably the only one I'll remember from my high school career. It uses simple principles to explain the most complicated concepts in the Earth Sciences. It's definitely a great hybrid of scientific application and entertainment!"

Byram Karanjia
12th Grade
Marshfield, Wisconsin
Currently a student at Harvard

"The Density Flow Model not only visually illustrates an obscure phenomena, it does it beautifully. It's pretty to watch. Students are challenged by the hypothesizing done before the experiment, and their understanding can be gauged by their hypothesis for the next experiment. The study manual is simple and concise. I wholeheartedly recommend this teaching tool to any science teacher."

Josh Rudlong
Naturalist
Good Earth Village
Spring Valley, Minnesota

“My kids have had no difficulties at all with the demos that I’ve done. Although we’d already covered density and done some work with air masses and fronts, many of them made incorrect predictions as to what they were going to see in the demonstrations. Since we did these on our ‘block’ days, they had plenty of time to try to figure out what went wrong and why. Excellent! It isn’t only me that loves this tank – the other teachers at my school covet it. Even the science teachers at the high school borrow it regularly. If it weren’t for our district’s budget crunch, I’m sure you would have already sold another six Density Flow Models right here!”

Ruben Giral
Earth Science Teacher
McDougle Middle School
Chapel Hill, North Carolina