Two years ago I had an excavator dig a 3/4 acre pond on high ground (it is 8 feet deep with a small cut of 10 feet deep). The reason I wanted it on high ground was to avoid the green, fertile, and often muddy water that my low-ground (6 acre) reservoir pond receives.
The new pond was filling up only from rain water, too slowly for my satisfaction. So, last spring and again this spring I had water pumped uphill from the old pond to the new one. After the first pumping the water looked beautiful. It cleared up in time and was amazingly blue-green in color with very little algae. It wasn't yet at full pool though, so this spring I did more pumping to bring it up to near the top. Probably one-third of the water in the new pond came from pumping water uphill from the old one.
The problem is that this year the surface of the pond is half-covered with a soft, light green algae. Rooted pond weeds are only just starting to emerge, and I'm hoping for more of them. My thinking is that more vascular, rooted plants will take up the nutrients from the algae, but I'm just guessing.
I do have an aerator scheduled to be installed within two weeks, but I have no idea how that may affect anything.
I could use some advice as to whether to treat for algae now, or whether to wait until midsummer to see if it abates. I'm not even sure why I have an algae problem. Is it because some of the water is from the old pond? There is NO runoff at all coming into the new pond. Any advice is very welcome. Thank you!
This photo shows the first pumping of water uphill on June 1, 2012:
This photo shows the new pond on June 10, 2012, after the first pumping:
This photo shows how the pond looks today, May 24, 2013, about two months after the second pumping:
