Question
I have a 1000 gallon koi pond with several lillies and pickeral plants in it.  I have a wonderful skimmer filter and waterfall but for some reason this pond is gonna put me in a mental hospital.  I can see approx. 4 inches under water and the complete sides of my pond are green and yucky.  I use clear zyme, algae blocks, green clean, salt and everything I have been told to use.  It is really murky water and I cleaned it out 3 weeks ago and it stayed pretty clear until this past weekend.  What is going on?  really this pond is not enjoyable it is a headache.  I thought that I could enjoy this but apparently not.  ANY HELP APPRECIATED

Answer
I'm sorry for the problems you have had.  Has it been hot there?  How old is your pond?  If it's new, it is normal for it to be green.  First, you must realize that as ugly as the algae is, it's part of the pond ecosystem and not entirely bad.  In the absence of higher plants, algae will also produce oxygen during the day and filter water.  That said, I'm sure you're dying for a clear pond.  My pond algae page is at http://www.fishpondinfo.com/plants/algae2.htm
The keys to a clear pond are lots of plants, shade, good filtration, good bacteria, barley straw, time, patience, and more plants!  To my big pond, I add small amounts of pond salt (<0.02%), barley straw, lots of plants, good bacteria (Microbe-Lift and BZT), baking soda, and koi clay.  That's about it.  The baking soda is to increase the alkalinity not for algae control.  I have never used algaecides in my big pond which is crystal clear for all but a few days a year and some years, every day of the year.  The first two years of my pond though, which is ten years old, the pond was opaque green.

If you only have a few lilies and pickerel weeds, you need to add more plants.  How many and what types of animals are in the pond?  Overcrowded ponds are more apt to grow algae but a pond without fish can also get algae.

So, forget the toxic chemicals and try some natural methods.  My site lists more.  Good luck!