Bent Fish

[Michael from Daytona]

Thank you very much to everyone who took the time to read and respond, sadly I lost both him and another from the same group overnight I did multiple tests this morning and got the same result so I took a water sample in to the local fish guy and had a chat to him, the good news is my water is fine, while I do have some free floating algae the nitrate level is very low (my water is always black/brown due to tannin staining from the walnut tree that used to cover the pool) he also ruled out FishTB as we don't have it in NZ, he suggested it may be a genetic issue caused by intensive inbreeding and triggered by the heat (I know goldfish are supposed to be fine at 24C but where I live we don't usually get enough sustained heat to heat the water that much, and while the lower layers take time to change the top 30cm of water has always changed quickly it's back down to 21C today)
If it is genetic I may lose the rest of that group, one of them is a little off today but still swimming ok and not bent at all, the others all seem normal.
I've checked the pump cables and they're all fine- the fish can't get near the pumps themselves, I have surge protecters on everything, we don't have many thunderstorms here so lightning is unlikely.
I do have three seperate smallish waterfalls to provide aeration as well as a couple of solar fountains, there's abundant oxygen weed on the floor of the pond, I do plan to get an aerator eventually but I'm doing this on a miniscule budget so that will have to wait.
The other thing the fish guy mentioned is possible scoliosis so I've thrown in some orange pieces just in case although they do get a lot of greens.
Other than that I'm not sure what else i can do, so I guess I'll just have to wait and see.

Interesting that you mention “bent” fish as a presenting problem. One of my immature (4”) koi developed bent spine a couple of years ago which I didn’t notice until looking into why the other 8 koi were harassing this fish. Fearing a contagious disease, I took him out and placed him into a 5 gal bucket, convinced he’d be dead by morning. The following day he was active and hungry and clearly looking pent up. I felt guilty about leaving him in the bucket any longer but I didn’t have anywhere else to put him. I have two 600 gal tiled ponds connected by a shallow stream with koi in the lower pond and 9 comets in the upper. I gritted my teeth and put him in with the comets, hoping he wasn’t going contaminate the water (both ponds share) and the smaller comets wouldn’t beat him to death. Well, they tried - chased him relentlessly for several days, but then they seemed to accept him. Fortunately, none of the other fish (including two plecos) developed his, or any other, affliction.

Over the following couple of weeks he behaved like a “normal” (despite his marked scoliosis) fish. In fact, he nearly tripled in size over the next year and today, “Capt. Hook,” as I’ve come to name him, has returned to swim with the big fish in the lower pond. His deformity is now barely noticeable under the layer of muscle he’s developed to counteract its effects.

I know this story doesn’t help you but I thought it might ease your angst to hear that sometimes fish that seem at death’s door can make remarkable recoveries all on their own. Capt. Hook certainly did.