I have had my P3A since January and love it. I use it for agriculture and of course enjoyment. I scout my fields, check conditions and crops or weed problems in all my fields. It's great! I would love to add a "simple" spot sprayer to my drone. I've seen the Agras, and $10k is a bit much! I don't need the gps routing and so on. I just want to be able to fly over a small patch of weeds and spray dribble some herbicide on it. We also keep our creek bottoms free of invasive plant species and this would be ideal to fly over to that on bad plant 100' out in a swamp and be able to apply the herbicide. I don't have any experience with servos and RC but from what I've seen it can't be that hard to do. Just a simple servo, that can be controlled remotely to open a small valve or pull a trigger on a little plastic tank. Think "small" water bottle sized tank, I'd probably pressurize it with a few pounds of pressure to enhance the dribbling of herbicide. Also thought about clear tubing hanging down a couple of feet from the drone with a nozzle on it to get a bit away from the rotor drafts. Obviously i'll have to test it and see what the rotors do to the spray. Looking for thoughts and ideas and exactly what to buy servo/rc wise. Kind of clueless.... self powered, remote controlled servo to push, pull, or rotate . . . ? Mini easy to operate valve?