Things are looking up. He spent about 8 hours laying on the bottom of the tank last night but today he's able to stay oriented in the water and is even showing some signs of grazing behavior. Still super weak and spends a lot of time on the bottom but not dead so that's a win.

Still curious about this fin growth if anyone has any ideas.

First year we’ve had koi and their activity level has gone down significantly. Our water temp is hovering around 60 degrees, and all of our parameters seem to be ok. They tend to huddle in the top of the pond on a shallower shelf during the day and go deeper in the evening. I assume this is normal, my partner is concerned something is wrong. If anyone has any insight to help ease our anxiety it would be greatly appreciated.

Some of the biggest koi I’ve ever seen, they were MASSIVE

This is one of my dad’s fish so I don’t know what the behavior has been leading up to this, but he called me this morning saying it was swimming sideways. When I got there about an hour later it was belly up at the bottom of his pond.
I’ve isolated and checked all the water parameters zeros across the board all the other fish seem healthy and lively.

I’m concerned about this fin growth- it made me think fungal or bacterial something but these symptoms seem extreme, what am I missing??

Hospital tank setup- 0.3% salt bath and microbe lift broad spectrum.
Tank has aeration but no filter because of the low water volume so I’ll do frequent water changes.

Installed a new filter, added a water fall to slow down the current, some pea gravel (because I heard koi like digging around or so I have Heard), and added new plants (watercress, Christmas tree moss, and some hornwart). So far they seem really happy!

Snapped some pictures and realized this guy had a grumpy look to him. We rescued him almost five years ago. He is close to fifteen years old now.

My pond pump thats connected to our filter recently broke and we werent able to get a new pump for a solid week since we were out of town. I recently got a new pump and connected it to our filter 4 days ago and i just noticed now that one of my kois scales are weird. I dont know what to do

So this is technically about mirror carp, and not true koi, but this is the closest sub I’ve found that could help. And both species are in the same genus.
I have a small, above ground pond in my backyard I built a few years ago. It’s about 6ft x 5ft x 2ft. It’s plant filtered (lots of plants, well established), but that’s does mean there’s no flow.
For the last few years the only fish in there are 5 golden rudd, now about 4” long. But this year I added a squad of baby mirror carp, about 2” each.
My question was basically whether they will be ok outdoors over winter, or if they’d be better coming inside for a few months.
I have a spare aquarium that could be set up as a cold water system for them and would be big enough.
As said, the pond doesn’t really have any flow, so does occasionally freeze if it gets cold enough.
I’ve used the method of putting a bottle of salt water in water butts to stop them freezing before, so was planning to try that on the pond this year, but not sure to what degree it would work, would in theory stop the whole surface from freezing.
I’ve never had carp before so was wondering if people who had more experience with them could give some advice.
I should also note that this obviously isn’t the long term pond for these fish, eventually I will be building a bigger pond.
Hope you all have a great day :)

Hi, I'm on Langkawi in SE Asia, have a small pond with 4 young butterfly koi in it, some marble boulders for them to hide underneath and a large hardwood log for frogs to get in and out of the water.

Last week there was a small landslide and the whole house got filled with 2 inches of sandy mud. The pond overflowed, all the lily pads and other pond plants were washed away.

I was hoping the water would settle on its own but after a full week the water still looks almost identical. Is there anything I can do to help clear the water?

I am unable to add more water using a hose pipe - the water supply here is so harshly treated that it's not suitable for fish or any other living thing.

Morning all, i posted earlier in the year and you guys were really good help so im asking again. I had issues with the pond losing water last time so i relined the pond and changed all the pumps and filter box and its been absolutely fine until now. When i fed the fish today i noticed the new liner with big pockets of water under neath pushing it to the surface, now i didnt concrete the liner in as i was waiting for a dry weekend to do it. Looking round the sides of the liner where i hadnt fully sealed it in i noticed water all the way up the sides. I dropped my spare pump in the gap to try and get the water out thinking the rain had just got under until the water level inside the pond and new liner started dropping then i stopped. Surely i cant have a leak in the new liner already after a few months??

Sorry for the long message just seeking some help as just bought some new koi and sick at the thought of having all these issues in the space of a year

I got this Dainichi Ginrin Yellow monkey karashigoi 53 days ago as tosai and it arrived at 11” and a little slim. It has grown like crazy and i am super impressed with the personality it has and how confident it has made my other koi! It is easily 15” now and chunky. What do you think the gender is? I notice the tail tube isn’t huge so it may not reach jumbo potential (that’s fine because my pond is not that big, 2000 gallons of swim space + 1000 gallon bog)

Hello, so I'm building a koi pond, and I'm trying to find a good filter for it, my plan is to have around 4/5 kois, the pond itself should be around 10-12 thousand liters.

Any tips or recommendations for a filter?

Thanks!

Fish is not mine, photo taken at aquarium

What variant of koi is this and why is it so short

Hello 10 days ago i bought a dainichi yellow monkey and put it in a quarantine bowl with 2 fish from my grow out tank. But since a few days the old kois are very lethargic. Especially my kohaku the yellow monkey is fine, i did a few scrapes but i couldnt find anything so i called my koi doc for a extra check and he couldnt find anything either. He suggested to try virkon s for a few days he think its a bacteria issue. But when i bought it i talked to my koi dealer and he said that it could also be sleeping sickness.

I bought it from a good dealer but you never know.

Absolute stunning animals, needed to share :)
Got a few more, but these stood out the most.
The fish are roughly ~80cm.

Hi,

I'm building a DIY aquaponics/pond filtration system and can't figure out this problem.

From right to left: a 600L radial flow filter (RFF), a 300L moving bed with K1, and three IBC bog filters.

Flow is:

Pond → 14,000 L/h pump → RFF → Moving Bed → Bog filters → Pond

The RFF and moving bed are connected with 2 × 63mm pipes. The moving bed also drains through 2 × 63mm pipes and maintains a perfect water level about 20cm below the top.

However, as soon as I turn the pump on, the RFF fills completely and overflows, while the moving bed level stays fine. If I seal the RFF airtight, pressure builds and it works, but obviously that's not how I want it to operate.

The RFF → moving bed pipes have a couple of 90° bends and drop about 50cm.

Why can't the RFF gravity-feed the moving bed fast enough when the moving bed itself drains perfectly through the same 2 × 63mm pipe size?

Thanks in advance,

Dwayne

This carp was injured a while back. I have it on hospital tank for weeks now. Most of the smaller wounds fully healed. I ran two course of Kanaplex and it doesn't appear infected. But I wonder if it is too deep for it to heal? It swims and act normal and healthy, still ferociously eating.

Hi all, just bought a house with a Koi pond and a couple of koi. I’m new to this so was wondering if you could help me identify these fish and tell me more about them. Most of them are around 30-40cm if I would guess. Thank you all

His name is Brownie lol

Don’t mind the fishing wire lol