Python No-spill (backflow Prevention?)

[allieharicot]

I just purchased a Python No-Spill from petsolutions.com. My dad took a look at it and is thinking that it is unsafe and if the pressure adjusts from the sink in any way, we will contaminate our drinking water in the sink with backflow. I searched high and low on the internet, and through these forums, not finding an answer.

I did find an item called a "check valve". Would this do the trick to prevent backflow into our faucet? I'd rather not drink fish poop. Is it possible to hook up one of these valves to a standard faucet?

Thanks to anybody who knows anything about this subject at all.