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