Hi Ozmosis, Welcome to Koiphen.
All 11 of my koi are very much basic pond mutts, the 9 kids are 11 yrs old and dad is close to 14; I also have an 11 yr old that I saved from Walmart. The kids were born in the pond and I've had the parents since they were a few inches long, they will have a forever home in my pond. I have a couple of them that most of my friends say "Only a Mother could love that one because its so ugly". But when you have a 2' plus koi come up to you and eat from your hand and he has been a member of the family for 11 plus yrs..... That alone makes them ALL beautiful to me.
I'm glad you decided to keep him, it looks like he has an amazing home. After watching your video on the koi I watched the video on your pond set up. You have an awesome set up, the water looks amazing and the fish very happy. I love watching them go through the tunnels from one pond to the other, hopefully they wont outgrow the tunnels

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Deb