3 ppm is sometimes suggested in the literature for killing bullheads and other resistant species, but 3-5ppm is more effective if any or a combination of factors are present: plankton blooms, heavy weed growths, suspended clay / turbid water,highly alkaline water above 150-200 mg/L - all capable of binding or absorbing rotenone. Water temperatures above 80F will detoxify rotenone quicker resulting in a shorter effective kill time. The more of the above features that are present the more the dosage should be toward 4-5ppm especially for bullheads. If the species you are killing are bass, BG, crappie shiners minnnows, shad then the 1-2ppm concentration is adequate.
Article - Pond Boss Magazine - Jan-Feb 2004 pg 24-25: "FISH ERADICATION: Use of Rotenone in Pond Management by Norman Latona. In-depth description for use of rotenone".
1. Rotenone is most effective in clear, soft, acidic waters.
2. Rotenone is absorbed by organic matter, clay and silt.
3. Rotenone breakdown is rapid above 70F. Above 80F breakdown is around 3.5-5 days.
4. Grass carp and threadfin shad are very sensitive to rotenone at 0.1 ppm concentration.
5. Green sunfish, goldfish and golden shiners require 2.0 to sometimes 3.0ppm.
6. Partial treatments of rotenone (0.1-0.2ppm) can be used for selective removal of sensitive species such as grass carp, threadfin & gizzard shad,
Last edited by Bill Cody; 08/21/12 08:52 PM.
