Hi, Over the last week or so our 1.5 acre pond looks like it has a "film" on the top in places. Looks like swirls of pollen or something. It has been fine until now. The fish are doing good as ever, coming up to eat and being active, no dead fish either. It has a few weeks since our last rain, could this be the problem? This pond is creek fed and has a few small springs also. We have waterfowl but only 3 ducks and 4 geese on it. Any ideas on what this could be? or what I need to buy to clear it up? Thanks for your help.