neo if you want a fishing pond I would not use chlorine. If it is for swimming or scuba and lined then , like a pool , it will clear the water. As you noted all color comes from sunlight. Black is a color mixture and absorbs all of the light spectrum. Water reflects the sky/color and bottom reflection. Black bottom = color absorption and dark looking water even though it may be clear. If the color is from suspended solids and is clearing I would wait on winter and see what you have. It may clear by itself.

cheezy1963 By the time symptoms appear in the soil the damage would be done. See this link.

http://www.pondboss.com/forums/ubbthreads.php?ubb=showflat&Number=37346&fpart=1

http://www.pondboss.com/forums/ubbthread...=true#Post50314