Question
I have alot of flowing agae in my pond.  Just this year I have already cleaned it 4 times.  The pond is 700 gallons large, has aquatic plants in containers (but the roots of the plants are coming out of the containers) I have 6 small gold fish, and minnows.  I made a bio-filter that acts as a waterfall also and using an the Laguna Waterfall Filter Pump. The sun was in direct contact with the pond from 10:00am to 6:00pm, so I put a canopy over it.  I do treat the water once in a great while with agae killer, but no luck.  Please help...thanks  

Answer
The long algae is usually hair algae.  It prefers cooler, flowing water in bright light.  Is the hair algae growing all over?  I have a page on pond algae at http://www.fishpondinfo.com/plants/algae2.htm with a number of ideas to try.  If you want to use an algaecide, AlgaeFix by Aquarium Pharmaceuticals is pretty safe (just kills crustaceans) and is supposed to work pretty well on hair algae.  The plants that need repotting, since they have roots in the water are actually helping to filter the pond water and compete with the algae.  If you don't have floating plants, you might add some of those.  Right now, my smaller ponds are completely covered in mostly duckweed so there's no real algae.  Of course, it also blocks light to any plants down below. Anyway, check out my algae page and see if you can find some things to try like barley straw, good bacteria, and various chemicals (not algaecides).  Good luck!

Robyn