Hi everyone new here to ball of spray. I have a somewhat new lake in Nor Cal wine country that is now in our fourth year. We developed a Sago pond weed issue last year and treated with Reward. This stunted the growth for a few months but the weeds have kept coming back.. Tried to get a stocking permit with DFG for grass carp but they will not issue for our area. Was told by our chemical supplier to use Sonar but was a bit surprised at the cost. Could buy a few new skis at the price of a single treatment. The lake is about 50 acre feet in capacity, no fish other than mosquito fish, and we do not irrigate from it. Have read a bit about Diuron sp? But many seem to recommend against it. Any advice from others who have has similar problems?