How to control algae in your pond . Updated: Jun. 22, 2010, 10:21 a.m. ... If you have the string-type algae, use a pond vacuum to suck it right out. For more on algae, check out.

The peroxide also works on the string algae in our koi ponds. For this I use the grocery store 3 percent product at about 1/2 gallon per 1,000 gallons of water.

They say the two types of algae that can take over fountains are pea soup algae, ... and string algae. Cleaning, chemicals, or making sure the water is properly aerated are all ways to control it.