My pond is 1 year old. I damned up a canyon last year and have about a 1.5 acre lake. At the damn the water is about 25' to 30' deep and runs back up the canyon around 150 yards to a spring that drops off a 10' waterfall and runs down into the lake. I catch alot of run-off from rainfall and have filled the lake up twice in 1 year. Each time I get a big rain the water is muddy like chocolate milk about has cleared up in a matter of 7-8 days. After a long dry winter the lake was down 8-10 ft. and I just had another big rain and filled it again. This time the lake hasn't cleared up in over a 4 week period. Can you tell me what has caused this or what othe rinformation you need.?