Hello Dylan,

Welcome to Frog Fourm.
I have always used an Exo Terra product called Aquatize as it is made specifically for amphibians.

Exo Terra : Aquatize / Terrarium Water Conditioner

I have to honestly say , I have never studied the difference regarding the ingredients.
I use the API ( stress coat -plus) for my discus; but not my frogs.

The Aquatize has an attached dropper in the lid.
This dropper lid makes it really easy to fill lots of gallon containers at once.
An easy 8 drops /gallon.