I used to use treated water all the time. I actually work in a lab and have it on a tap. I'm getting a doctoral degree in Entomology and one of the arachnologists in our department stated that treating the tap water really wasn't needed and most of the tropical tarantulas he's worked with for decades have been on tap water so I stopped using it. Now my guys have been on tap water for I think 3 years or so with no ill effects.

Now frogs are another story. I'll have to get used to all the cleaning and treating. I'll also have to make sure I don't forget and rehydrate coco bedding with tap water.