That's pretty cool that you know your water chemistry just by looking at the water - are you sure you need to be a psychiatrist - JUST KIDDING. I bought a bunch of test kits when Aquarium Sales went out of business. Does anybody know if they can go bad? Anyway, they just sit inside the stand on a shelf. They're covered in dust. Sometimes I think I'm just too busy to have this hobby. By the way, in case anyone was wondering, it's been pretty **** expensive too.