What's been killing my frogs?!

[Krispy]

What kind of filtration? Seen a few issues like this around the web. The most common prognosis was, bacteria stashed in the corners of the tank in/under the silicone. Id scrap the tank, or fully submerge the tank in diluted bleach water for a few hours, scrape it, and re-seal it. Maybe soak it again once the silicone cures to be sure.

With 10 of our own in the same tank. We change water 2x weekly and the filter once a week. Bad water will kill every time.

Seems like heath issues in amphibians are on a sharp rise as of late....