Could be, but my pond location is in a low spot surrounded by hills and trees so I don't benefit from the ripple effect of wind moving across the surface to agitate the water. If your pond bottom has a lot of organic matter and no oxygen then the right bacteria required to eat the muck from the bottom will not be present. I really couldn't say for sure that the bacteria that I added was the only factor in eliminating the muck. I believe that the combination of getting rid of the surface obstruction WM and DW along with aeration which circulates the useless water from the bottom to the surface and back into the water column gets the bacteria on the bottom the elements needed to remove the muck on the bottom. Your right, for 100 years ponds haven't needed aeration to survive and my pond probably didn't need it when it was new some 40 years ago but old age has set in and it needs a pick me up. I am sure that I have left out important details and I am only relaying to you what I have noticed in restoring my pond, and am sure that more educated and wise members will be along to help out. I will say that I was very impatient at first and wanted immediate results but luckily I was distracted with other project that needed my attention and was happy to see that things were working out for me 3 years later with the pond.
