Sick Koi Help Needed

[LillieB2]

Hi everyone! So recently I have had a couple of my larger koi become very lethargic and resting on the bottom of the pond. One even slowly rolls onto its side. It has been happening since Thursday. I have stopped feeding and since yesterday (Saturday) I have slowly added salt up to 750g in my about 1000L pond possibly more. I need to measure properly.
I have given them peas today incase of a blockage. As more time goes on I'm freaking out more and more and worrying about my other fish.
I introduced two new koi on Tuesday but they are both perfectly healthy, no worries with them at all. I have posted in different places too and I have had a couple comments mention sleeping sickness! I just really need help with this in desperate. I will attach some videos below of my pond set up and the fish. Any help would be greatly appreciated! Any other ideas for sickness and things to help including air pump recommendations etc etc.
Thanks in advance!

 

[bgarthe22 39]

Hello and welcome to TFF. Sorry you’re going through this.

Before ideas/suggestions can really flow, please fill out the Emergency Template here at the site. It will provide useful data and better enable us to make informed suggestions. Also….your Vids are both non-existent when I click on them. Lastly, pics of the fish in question always help along with detailed behavioral tendencies.

 

[LillieB2]

So sorry where do I find the emergency template? I've only just joined I hope these videos come through properly

 

[bgarthe22 39]

I’m sorry. I bounce around several Forums and, here at TFF, there is no such template. What would really help to know is your water parameters like temp, GH, pH, and KH. Tell us your feeding schedule and with what foods and whether you Quarantined your new fish before adding them. Any and all details, no matter how small, would give a clearer pic. Btw….regrettably, I still cannot get your vids to play.

 

[LillieB2]

Hahaha all good. I don't know the temp or gh... Ph is sitting quite low at around 6.7 and kh is extremely low almost nonexistent at 35.8. HOWEVER it has always been this way as that is just our tap water and it is stable. I've taken over this pond recently from my dad because no one spends time with the fish or cleaning the pond but my dad never used to check anything and we've never had any issues haha. We've just come out of winter so for like a week I'd been feeding them twice a day. Morning and bit before sun goes down but during winter only a small amount in mornings. But of course since Thursday now being Sunday I hadn't fed the fish. We just have standard floating pellets to feed them. We did not quarantine the fish as we have never had an issue with it in the past. We've had koi since I was a little baby really and in the 24 or so years of having the pond we've never once quarantined koi haha. The videos are just showing the fish slowly rolling onto its side on the bottom of the pond and then swimming away as I disturb it! What else is there to add... The two big affected koi (just one rolling) are around 40cm long and 10 years old I would say. They're the only ones affected. However I may have noticed a baby around 9cm long laying on the bottom with clamped fins but I'm in panic mode so anything is a bad sign to me right now

 

[LillieB2]

Hahaha all good. I don't know the temp or gh... Ph is sitting quite low at around 6.7 and kh is extremely low almost nonexistent at 35.8. HOWEVER it has always been this way as that is just our tap water and it is stable. I've taken over this pond recently from my dad because no one spends time with the fish or cleaning the pond but my dad never used to check anything and we've never had any issues haha. We've just come out of winter so for like a week I'd been feeding them twice a day. Morning and bit before sun goes down but during winter only a small amount in mornings. But of course since Thursday now being Sunday I hadn't fed the fish. We just have standard floating pellets to feed them. We did not quarantine the fish as we have never had an issue with it in the past. We've had koi since I was a little baby really and in the 24 or so years of having the pond we've never once quarantined koi haha. The videos are just showing the fish slowly rolling onto its side on the bottom of the pond and then swimming away as I disturb it! What else is there to add... The two big affected koi (just one rolling) are around 40cm long and 10 years old I would say. They're the only ones affected. However I may have noticed a baby around 9cm long laying on the bottom with clamped fins but I'm in panic mode so anything is a bad sign to me right now

I fed the fish peas today as my dad suspects a blockage. All of the koi including sick ones ate some! Before spitting them back out lol. But about 5 minutes later I checked back out and all the food was gone so I assume they had some to eat. I also checked over the most sick kois body and I see absolutely nothing on it. It had a couple very very pale red veins close to where it's tail starts but it didn't look concerning to me

 

[Naughts21 93]

I can see all your mini video clips. Beautiful pond and garden!
From your additional information there are two theories -
1) the new fish have introduced a pathogen giving the fish internal bacteria or
2) the reintroduction of pellets in sluggish digestive systems has caused bloat.

I’m not aware of salt being a treatment for internal bacteria but it won’t do any harm so leave it in for a few weeks (2-4?).
If it’s just digestive issues, stop feeding pellets for a couple of weeks and see if it resolves. The peas could help but I would just fast the fish now. If the fish recover, future pellets can be soaked before giving to the fish to prevent recurrence.

 

[emeraldking1 52]

If you're just coming out of the winter, it's normal when koi are lethargic. Mostly the bigger ones need more time in comparison to smaller ones. That's the experience that I always had with my koi. Also the water parameters will be at a different range when coming out of winter than usual. If you've added new koi, they haven't been hibernating as the ones that were in your dad's pond. So, those will be swimming in a normal way.
I also have to mention that koi which have hibernated, will be a bit weaker and need time to adjust again.

 

[bgarthe22 39]

Good advice given above. I might add that colder water temps require low protein food and food to be given at this time should be the wheat germ type. In colder water (below 60) koi cannot digest protein. Going off food entirely for at least a week would be my starting plan. Then wheat germ koi food would follow.

Interesting……koi generally prefer harder water and yours is soft (low GH), low pH, and low KH. But, if this has worked for you, then that’s great. I know that when I accidentally allowed my 600g basement koi pond to get too soft, bad things started happening with the fish. Soon after I gradually raised the GH, things got better. When I took the basement overwintering koi outside to the 3,600g outdoor pond, it was warmer and I resorted to regular protein koi food.

When last I had a similar thing happen with what looked like a perfectly normal fish, I was pretty sure it was due to the stupid agricultural crop dusting done around us. Those chemicals are MAJOR trouble for fish.