Originally Posted by FishinRod
Originally Posted by Bill Cody
Remember you will want the pond to be as healthy as possible with low chemical residual and less long term impact after the fish are kill.

This implies that there is a chemical residue after treatment! I don't recall a Pond Boss discussion where we considered that.

I just checked the Wiki (I know) page for rotenone. Apparently the residual rotenone clears more quickly from rivers than it does from ponds or lakes.

I assume this indicates, that in static water, the chemical degradation rate is significantly lower and/or the lack of dilution allows the chemical to remain dangerous to fish for a much longer time in ponds.

Conclusions:

1.) If you pull the pond volume down by 90% and treat with rotenone at the prescribed concentration, then when the pond is full - the remaining chemical is at a minimum of 9 times more diluted than the effective dose. It should then be safe if your initial treatment was performed at the correct concentration?

2.) Do not lose patience if your pond is slow to refill due to low rainfall conditions. If you stock your fish "early" while the pond has barely enough water for the stocked species, there is a chance the fish could be subject to a significant concentration of rotenone. .

On this note. When Rotenone was applied to my pond, The water volume was down Approximately 60%. We applied chemical for 12 acre feet. Luckily we have a fairly large well to refill the pond,
24 hours after application the well was started, 5 days later (6.5 acre feet) of water was put into the pond. The following day test fish were put in, They survived over a 24 hour period, The following day 100# of FHM were stocked.
I know we sped up the natural process of filling the pond but this tells me Rotenone is not lethal for very long
If you can go from application to reintroduction in a 6 day period while only increasing water volume 33% it can't have that long of a lasting effect