Had an existing koi in the pond and got 7 more this year from a local pond. Age unknown but they probably tripled in weight and added several inches since mid summer. Amazing how fast they grew. The gold one is at least 24".
So far the water looks to have good clarity. It is my suggestion to start taking water clarity measurements using a homemade Secchi disk. Use it regularly as in once a month to monitor the water clarity and quality of the pond. As the koi grow large it is very often my experience that the water clarity gradually becomes more and more turbid as determined by Secchi disk measurements. Suspended sediments from the koi bottom feeding activities are enhanced by bottom aeration as the currents tend to keep ultra small dust sized sediments in suspension. IMO 7 large koi in a 1/2 ac pond will eventually reduce the water clarity to 12". If this happens over time at least you will know why. Do the secchi measurements and lets see how wrong I am in my estimate. Come back year at least once a year and report your results. We should all learn more about koi. Secchi disk does not have to be exactly 8" dia ( 7"-10" is ok) as long as you are using it in just your pond.
Last edited by Bill Cody; 10/23/2408:47 AM.
aka Pond Doctor & Dr. Perca Read Pond Boss Magazine - America's Journal of Pond Management
So far the water looks to have good clarity. It is my suggestion to start taking water clarity measurements using a homemade Secchi disk. Use it regularly as in once a month to monitor the water clarity and quality of the pond. As the koi grow large it is very often my experience that the water clarity gradually becomes more and more turbid as determined by Secchi disk measurements. Suspended sediments from the koi bottom feeding activities are enhanced by bottom aeration as the currents tend to keep ultra small dust sized sediments in suspension. IMO 7 large koi in a 1/2 ac pond will eventually reduce the water clarity to 12". If this happens over time at least you will know why. Do the secchi measurements and lets see how wrong I am in my estimate. Secchi disk does not have to be exactly 8" dia ( 7"-10" is ok) as long as you are using it in just your pond.
I would like more koi but understand that they can root and stir things up so that is why we only have 7.
The pictures are a bit deceiving as the one orange one is probably close to 30 inches and two others over 24 inches. Several rarely feed on pellets but have gotten very round so they are eating the plants which is great.
Water visibility goes down mid summer with suspended growth but after the cold snap it cleared up in days to probably close to 48" visibility. 9.5' in the center so they must go to deeper water often as I can't see them sometimes.