Foam on lower pond surface . . . (?)

[SangyPA]

My pond has been in near constant circulation (except when frozen) for almost a decade. Just this spring, the pond has developed for the very first time, a very noticeable, and white "foamy" accumulation in the lower pond. I have had no fish for a couple of years. I have never tested the water and have not treated it with anything since the last fish was eaten by a raccoon. Is there a "restart" button for me that won't require a complete do-over?

 

[sissy]

do you have frogs . If you have no fish you can use some peroxide . Not sure what else because no fish so no spawning . Unless something sent you some fish from heaven

 

[j.w]

@SangyPA
Foam maybe from excess nutrients, not sure?