had quite a bit of this coontail in my one acre pond - after Bobs advice I purchased some Aquathol liquid and am treating my pond in thirds spread out over 30 days. My first application worked well - my question is this: the first area I treated took 98 percent of the weed out - but there are a few small plants left along the shoreline. Should I spot treat those? Is it necessary to kill every single plant and if I don't will it come back? Thanks