Rotenone is a Federally restricted-use piscicide (pesticide for killing fish) and therefore requires a pesticide applicators license - at the very least - in all US states.
Liquid rotenone is currently not in production (for the past 18 months) and won't become available again until sometime in late 2025 - supposedly.
Greg Grimes (in GA) probably has some liquid rotenone remaining; otherwise, only powered rotenone is currently available - and only in 110 lb kegs. Btw, liquid rotenone - when it was available - was well over $120/gal in bulk.
A typical average rate for powdered rotenone is 8 lbs/ac-ft (= 1 gal/ac-ft of the liquid).
IMO, rotenone is "safer" to apply (with appropriate PPE) than hydrated lime - which is extremely caustic - but neither product is pleasant to handle.
