The RODEO and ROUNDUP (the later should not be used IN the pond) are completely ineffective on coontain, duckweed and watermeal. WEEDTRINE D would be marginally effective IF you use enough AND keep going back after survivors on a frequent, short-interval basis. However, REWARD would be a much more economical alternative to WEEDTRINE D.

The pond's size may ultimately dictate the best treatment option. 2.5 acres may be enough to justify this strategy, which is to use some SONAR Q pellets and some SONAR AS liquid (pellets to primarily target the coontail and liquid to target the duckweed/watermeal - though both products will "assist" each other). The liquid will provide a quick concentration "spike" while the slow-releasing pellets will help to sustain and prolong the concentration - especially under the prospect of potential outflows (hopefully minimal).

Also, WEEDTRINE D or REWARD (both are diquat) may be used to treat any duckweed that becomes stranded above the waterline - whether on stumps within the pond or along shoreline areas. If the duckweed or watermeal isn't touching the SONAR-treated water, it isn't going to be controlled by the SONAR.

QUESTION FOR YOU: given the nutrient inflows you described, has your pond experienced a lot of filamentous algae problems?

Kelly Duffie
Cypress, TX