I don't have a pond, but I do have a large livestock water bin to fill for my ducks to swim in. The problem is that I don't want mucky, stale, mosquito-filled water in it, and I can't afford to keep dumping it out and re-filling it every five minutes (cause that's how quickly they get it filthy) I'm wondering if there's some sort of cheap duck-safe additive I can put in the water to keep it from going stagnant. Would a water pump to agitate the water work??? Or is there some sort of pond additive I can put in there to keep the water mosquito/smell free??? Thanks!!!