We were tempted to take a sip out of this pond as it reminded us of a nice hot, cup of tea. The discoloring of the water occurs because the pond was built right below a pine tree. Over time, pine needles that fall inside the water will create this effect. You can eliminate this problem by either installing a net to provide cover or routinely skimming leaves from the surface of the pond.
Once all the debris are removed from inside the pond we can start to refill it with dechlorindated tap water. The large koi that have been slowly acclimating to the new water can be placed back inside the pond. Since this pond was well shaded it stayed this clean for a year. Additional steps you can take to keep it clean are less fish food, periodic water changes, and routine filter media rinses.