algae

my sister is having a problem with green algae in her pond. What can she do to get rid of it? Thanks

Does it look like pea soup or does it look like long green strings?

How much of the surface is covered by water plants? Does she have fish?
Does she have a filter system? Is it a liner pond? How deep? How many gallons?

Depending on how many gallons she has she might go to a pond store and ask about a U.V. Sterilizer.

Thanks. I really don't know much of that. She lives in another state. But I will pass on the information. Thank you

What do I do if it's pea soup with no strings? It's a small concrete pond, maybe 60 gal., with one fish - Spot - and one plant, which I added today. - Julie

The best thing for pea soup algae (which is a single cell aglae as opposed to other algae) is to get a UV filter. It's a UV light that kills the green cells as the water flows through. In only a couple of days, your pond will be crystal clear. There are other options too....a) more plants on the surface to provide shade. Sun is the main reason you have algae of any kind. b) minimize the fish food. Both leftover food, and excessive fish poop are great fertilizers for algae. c) barley ball or pads-barley breaks down into basically the same thing as hydrogen peroxide, and kills algae. The more oxygen you have in the water, the less algae. d) any kind of pump that promotes better oxygen flow.
Julie-If you only have one fish, you can take him out, flood the pond, de-chlorinate, and start over. Summer and heat will always cause algae.
The green stringy algae you can dump a little peroxide on, to kill it. It won't harm the fish.