Hey good to know about that amphibians are a good indicator of a healthy ecosystem, because they absorb all the surrounding chemicals from the environment through their skin.

We recently switched out our pool cleaning system from chlorine based to a Ionizer-Heavy Metal system where it dissolves copper and silver into the pool water to kill algae and bacteria. Must be less toxic as all the frogs and toads and even salamanders have returned to the area and are loud as hell at night!

I can recall a time when the pool smelled of chlorine, and there were no frogs around. Just lots of pesty insects. Not the same!