Pond Boss Forums INTRO Questions & Observations 3 Acre Koi Pond- New Windsor NY: Pond Care guidanc

Edward - Nice transition to your own thread.

Six main things are going on in your pond to create the majority of the water turbidity.
1. Koi are morphologically the same and identical to all the body structures of common river carp (German imports) except the Japanese have breed this sub-specie or variety to have colorful body markings.

2. Koi and common carp feed by digging or rooting into the sediment for gathering bottom oriented foods - they are omnivores. They have no stomach thus they cannot binge feed and rest for long periods between feedings. Koi-carp feed and root in the sediments many hours a day to keep food moving through their intestines for growth and nutrition. Rooting in the sediments produces a cloud of roiled sediment up around and behind the fish. I have watched koi feed and dig into the sediments clear up to their eyes.

3. Aeration methods are designed to move water and keep it moving for circulation. Circulating water currents helps keep very tiny sediment, silt, and detritus suspended into the water column - cloudy - turbid water. Most of the sediment and detritus particles in the water column will be 0.1 to 50um sizes - very slow to settle to the bottom. see #7

4. Bottom rooting activities help keep bottom sediment nutrients, organic decomposition particles and clay-mud particles resuspended into the water to stimulate more growths of decomposition bacteria and phytoplankton in the water column - both of these add to the reduction of water clarity. As noted feeding the fish always adds fertility directly or indirectly to the pond. More fertility causes more plants to grow. In your case the plants are tiny phytoplankton that when abundant often gives the water a green or brown hue.

5. The small catfish-like fish in one of the koi pictures look to me to be bullheads. Bullheads are also bottom feeding and sediment disrupting types of fish. True catfish have forked tails and bullhead tails are rounded, Some angling with worms on the bottom should allow one to catch a few and determine if catfish or bullhead. Large catfish will also disrupt sediments but not as much compared to bullheads.

6. All these activities of bottom feeding fish keep natural submerged vegetation from growing in that they are eating it or keeping it from getting established. Submerged vegetation usually does a good job of reducing (nutrient absorption & competition) the amount of bacterial and phytoplankton growths and plants tend to cause suspended sediments to settle onto the bottom. Almost always ponds with good amount of submerged plants have clear water.

7. Generally during winter when the bottom rooting fish are more dormant due to cold water, they feed less and water in winter is usually the clearest compared to warmer water temperatures when all the fish noted above are most active.