Question
I have a 18' x 21' pond. The depth varies up to 3'. I have a liner, skimmer and biofalls filter. There are several koi and goldfish. We had a bad storm and dirt ran into my pond. I shut the falls off 2 days ago hoping the debris would settle. Today I hosed down skimmer and filter parts and turned everything back on. The water is still very brown. I can't see my fish. What can I do?

Answer
I suggest a coagulant.  For example, Accu-Clear by Aquarium Pharmaceuticals is a polymer that binds to suspended particles in the water and makes them either sink or be sucked into the filter.  It does use up some oxygen so be sure to aerate well.  Also, believe it or not, koi clay is used to help settle out a pond (mostly from algae) but I think you maybe don't want more dirt in there!  You'll have to rinse off the pre-filter a lot while the dirt is being coagulated.

For the future, you may want to build a diversion around the pond for runoff.  Check out these pages on my site about storms and building a runoff diversion:

http://www.fishpondinfo.com/ponds/storm.htm
http://www.fishpondinfo.com/ponds/pcare2.htm#dirt

Good luck!