You can remove string algae by hand. Gently,
as broken off pieces will grow again.
I do fish by gallons. 1000 to begin with for koi, 100 for
every additional koi, 20-40 gallons per goldfish.

kathy :-) www.blogfromthebog.com
Pond 101 page for new pond keepers ~
http://hometown.aol.com/ka30p/myhomepage/garden.html