I'm going after the watershield/dollar bonnet in my pond in a few weeks during green up. I ordered some Polaris and methylated seed oil surfactant. I've read the label, but it isn't all that clear to me. I'm trying to spray about 1/2 an acre in a four gallon backpack sprayer. I could bust out my 25 gallon sprayer, but I think the backpack will be easier, if slightly more time consuming, as I will have to get out in john boat to get to some. Thanks.