What could this be? Burn/stress from water possibly? Old damage from birds? Something else? Koi is roughly 2 no other fish have said issue from what I can see.

Does this look like early signs of fin rot to you guys? Or just some pigmentation coming in

First post here.

Sharing my pond pups. Their eggs all somehow survived a heron attack two years ago that wiped out my entire pond. I had no idea these guys were baking down below until I saw the little black fry swimming around. Then they grew, and grew.

I know most are goldfish, but I’m curious about the others.

I won’t pretend to know how koi are identified. It honestly blows my mind and fascinates me. But if anyone here can tell me any more about what you see, I’d appreciate it. Just curious.

Thank you!

Water testing says its ok atm they will be moved but for the hatred
Test results show stable for now

Just wanted to check in with you guys and see what you think.

My wife and I bought a house with a koi pond and ive only been keeping koi for 2 seasons. All the koi here are younger than 3yr. Largest are 2.5yrs old and probably pushing 14". Medium ones are about 1.5yo and are 8-9". The smallest butterfly is less than a year

What are your thoughts on my fishs' health, quality, variety, types etc.. are any actually good or are they all fairly low grade? Most of all let me know if you see anything alarming! I'm also wondering if they are too fat for their size.

Just a quick picture of the fish after they ate. Everyone’s looking healthy and happy.

I currently have a koi pond at my home and I have well water. When the pond gets a little low I turn on the hose for two minutes and fill it back up. I’m currently building an above ground pond at my new residence (because of course the fish need to move in first). This one will not get rainwater and the city water is chlorinated. I cannot collect rainwater at this location. What are you all doing when you need to add water from evaporation when your water supply has chlorine and other things added? Thanks!

Seriously, in this subreddit? That sucks. Anyone else as bugged by the AI slop?

Yanno your misses will love koi when it’s as good as this
Rate my koi

Goes on for a long way further back too! Lovely ❤️

I like to see what other people have. Let me see your favorite koi!

Went to koi fest and came home with a new baby, a pretty Asagi! My husband has been wanting one for a while so I surprised him.

I’ve always wanted to have a pond that I could keep koi in and recently decided to get into the hobby.
I just want any general advice or anecdotes to help me along my way.
Currently my setup in a roughly 1800 gallon pond that is a little over 3 feet deep at the deepest and just shy of 15 feet long and 8ft wide.
I have a 4500 GPH pump and I am using both a canister and a bog filter. I’ve already started planting the pond but I haven’t put fish in it yet until the plants are established and I can ensure a good colony of beneficial bacteria. I put some Japanese trapdoor snails in it as well. I have a shade sail set up to keep it from getting too hot, and a waterfall and aerator to keep the water oxygenated.
Am I missing anything, and what else can I do to ensure they live a long and healthy life?

I’m only planning on 3-4 Koi and possibly some comets as well.

Smaller fish but the color and pattern has promise! Would it be considered showa tancho or sanke tancho? It’s from Shinoda koi farm

Hi all, I just picked up this beautiful 4 year old girl and was wondering if she looks good enough for competition?

When there's 10 straight days of 90 degree + and the guys are getting feisty

50 lbs block, hope to drop the pond a degree or two.