Squawkbert

Guessing: It shouldn't hurt the aerobic bacteria at those levels.

It sounds, generally, like the chances of melting a plant are pretty proportional to the plants growth rate, except for mosses.

Fortuna Wolf

Oh, I remembered one more thing. I was treating a nanotank for a cladophora infestation (which also happened to have duckweed). 2.5ml/G, just under the toxic dose for peacock moss that was also in it.

A week's worth of twice daily treatment bleached 95% of the duckweed and killed most of it off.

Survivors: Java fern, Peacock Moss, Eleocharis, Marsilea
Dead: Cladophora, Duckweed, other algae.