Flatworm Exit

[Kabong]

When I've treated with FWE, Ive noticed the major effects on other critters other then flatworms are
Fan worms who will hide out for up to days afterward, Doesn't appear fatal though.
and
Mini brittle's hate the stuff they go crazy, Coming out of the rocks and trying to get away. Does not appear to be fatal though, But there a little harder to keep track off. So some loses are possible.

However I don't think I would treat without removing any prized echinoderm's. (starfish, urchin, cucumbers)

other then that Ive treated regular dose and double dose with no visible deaths.

I had a 10 gal that was invested with them and rock that was also covered in apstasia dosed and left it in with no water change in it.
In the end no flatworms, no feather dusters, and no brittle stars to be seen.
So in other words long term exposure is deadly.