So why, I wonder, am I always pulling out yards of string algae?

Algea of any kind needs nutrients to grow.....pea soup algea needs lots of
sun....string algea does not. I have had it even grow ON the very plants it
is supposed to dislike. Go to the nursery and get a small bag of 0-0-60 ....if
you can find it this late in the year and add a teaspoon of it every week or
two....it will cause your plants to grow like crazy and starve it out. If you
can not find that....go to the grocery store and in the spice section get a
small jar of alum....it is used for canning and if they don't have it they can
get it for you. Use only 1/8 teaspoon and then do it again in 7 days....that
treatment will last a year. If you are doing frequent water changes
stop....you have enough plants that you don't need to. Adding new water adds
new nutrients. Lastly in 100 gallons you should have no more fish than 4 or 5
small goldfish if you have even one more than that you are over stocked and
that in itself is the problem ... .all fish poop and that feeds the
algea.....remember algea is a plant and all it needs is food and light to grow.
Good luck Jerri

http://www.fringeweb.com/Ponds/JerrisPond