ELODEA CONTROL I Have a 5 acre pond, 10 foot average depth, well water fed, no outflow. Have used a contact killer material in the past but elodea reoccus every year. This year tried Sonar Q, 120 pounds distributed May 1. Tested 11.6 ppm mid June. Added another 40 pounds mid June. Only about 10% of the elodea is bleached, remaining green and healthy looking. Mats of elodea have come to the surface and float. Doesn't appear that the Q is doing the job I expected. Need advice . Thanks. Frank

I have excellent control of Elodea with Reward. Maybe other will chime in on why SOnar is not working. Have you had lots of rain?

you have not given Sonar enough time to work, based on my experience it takes about 90 days before full results will be observed. if you get a lot of rain you will need to reapply to keep floridone rates high enough.

drop a line around Aug 1 with your results.

If the elodea is matted out and not actively growing as fast as it was, the Sonar will not be as effective. I agree with Shan that you need to give it more time to work.

Not to speak for Kelly Duffy, but in the past he has recommended burning back vegetation with a contact herbicide in conjunction with a Sonar app. The concept being that the vegetation will attempt to rapidly regrow, thus facilitating the uptake of the Sonar. This may be something to try if you don't start getting some results. Again, I don't know if this approach is applicable in your situation.

Fishman,

good idea, thats the approach I take most of the time. clean things up then eradicate the problem