I'm no biologist nor a tadpole expert, but I believe tadpoles early in development still have gills, and can breathe underwater like a fish. Tadpoles further along in development eventually grow lungs, like the frog/toad they are becoming, and need to surface to breathe. I have seen thousands of tadpoles surface on my ponds and have never had a DO crash. While I have no clue if this is a new development for your bow or not - I just wanted to try and help with my own observations/experience. I do not think tadpoles surfacing is a sign of low DO, they are merely breathing. You could still have low DO...just that "piping" tadpoles is not necessarily evidence of low DO conditions.

Have you performed any tests on your DO?

Many men go fishing all of their lives without knowing that it is not fish they are after. ~ Henry David Thoreau

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