Koi Died

[Paul Buccetti]

I garden in southern CT and when my pond finally was clear enough to see, I lost my two largest koi (17" and 21") and one or two smaller shebunkins. I have two smaller koi - one 8" and another probably around 4" (I haven not seen the 4" one yet) and handful of shebunkins. I have a heater in the pond and believe it's working. This year was one of the coldest we've had since I've had a pond. I've checked out some of the other threads and it looks like there could have been an oxygen or nitrogen issue. I'll get the water tested as soon as I can but does anyone have any other ideas? What should I do next year to help prevent losing any more fish?

Thanks!

 

[CometKeith]

Hi Paul. Welcome to gpf and I am sorry about your fish. Most people here will want more information about your pond before they can give you an answer.
Can you describe how large your pond is and how many fish are in it? Also do you currently have any aeration and have you done any tests? If it is an oxygen issue usually the largest fish are affected first.

 

[addy1]

Welcome to our group. Like cometkeith says, give us some more information so people here can help you out.

Sorry about your fish.

 

[callingcolleen1]

I am sorry to hear of your loss Paul. If the largest koi have died, it was most likely due to low oxygen as the largest koi die off first if the oxygen was low, cause the largest koi need the most amount of oxygen.

To prevent this from happening again, I suggest that you leave a pump with a good filter running all winter long in front of the heater to evenly heat the whole pond and that will also help keep a larger hole open in the ice. I do not suggest using a bubbler as the air line tends to freeze off when extremely cold.

I have been wintering my big koi since 1991 and they are still very alive and well and have been through some of the worst weather that Canada can have, over the many years. People are way to concerned about the water temperature, worried that ice cold water would be harmful, meanwhile my koi live in ice cold water for the last 24 years and they are just fine!

 

[Big Lou]

Sorry about you first Paul. Welcome to the forum. Oxygen depletion sounds like a probable cause.

 

[Dave 54]

Sorry for your loss Paul , by the way did you take those readings prior to or after finding your koi had died and if so what where they please ?
Did you run a waterfall throughout the winter ,months or did you it off prior to winters arrival did you also give your filter a good clean prior to the winter period and lstly could you please tell us if you cleaned the bottom of the pond prior to winter ?

Dave

 

[Tula]

Welcome to our friendly little forum! I agree with others, it sounds like a low oxygen issue.

 

[Lisak1]

@Paul Buccetti I hope you check back soon so we can learn more about your pond and what may have caused your fish losses.

 

[Paul Buccetti]

Thank you all! What a great response! My pond is about 3' x 10' and 2 1/2' deep. I have not yet tested the water as I need to find a good test kit. I did use a heater but do not keep the water flowing. I've done keep the fish alive for 15 years this way but it does make sense that there was not enough oxygen. I had 4 koi - 21", 17" (the two that died) 8" and ~3". There are probably about 8 shebunkin and comets. I realize now I may be guilty of having too many fish in the pond.

I remember when I first started with my ponds reading an article not to circulate the water during the winter or you'd end up with a pond of slush and dead fish. Rigging it up so the water flows through the heater may prevent that issue. One the weather here clears up a little more, I'm planning to get better dimensions and also start adding some fresh water. Make sense? Any advice on how to calculate how many fish you can put in a pond without making it unhealthy for them?

 

[Dave 54]

I think I see your problem and that is one of depth you have a pond 2.5 ft deap yes ?
The shallowest recomendation for koi is 4.5ft in depth of water , I think as you've said yourself this has been the coldest winter on record , I've a feeking that the winter simply became to hard for them to handle berhaps a new pond is recomended this year on that is 4.5ft or deeper if you wish to keep koi and about 3.5ft in depth for goldfish .
This should help reduce further casuallties if you get another perhaps even colder winter on record next year what with the way global warming keeps going an all.

Dave

 

[j.w]

Paul
Sorry about your fish loss and yep I think your pond maybe be too small and also too shallow for you fish and maybe it's time to get the shovel out again and get diggin

 

[slick]

Oh man i feel for you mate like Dave 54 says depth for koi is key but also is water quality, when winter comesi leave every thing running as it is in the summer air pumps water pumps filters etc the biggest killer in the winter is bad water build up of bad stuff pond iced over toxins build up fish cant breath but man i hate to hear about the death of any pond fish gold fish and koi im a koi nut my new pond has a water depth of 5 feet and a big bottom drain to remove all the bad stuff.
people say that where koi are involved you dont keep fish you keep water.

 

[Lisak1]

I'm going to disagree with @Dave 54 on this one. Many many MANY ponds in our climate (northern Illinois) are only two feet deep. Koi do well in the winter in ponds of that depth. We have seen ponds that depth with koi that are 20+ years old. Big, beautiful, healthy koi.

I would lean more toward overstocking. That's a lot of fish for what I would guess is about a 600 gallon pond. The extra cold weather may have added the last bit of stress that pushed your fish over the edge. Did your pond ice over?

 

[Dave 54]

Why should you disagree @Lisa1 if its been an extra hard winter on these fish then its going to claim them there is a recognised depth for keeping koi at 4.5ft in the US Europe South South African and UK koi worlds the minimum depth is that of 4.5 ft if the pond has frozen over then toxins build up then you are going to see koi deaths , I cant answer for shubunklins as I dont keep them but the senario is the same .

Dave

 

[Lisak1]

I don't think it was the pond DEPTH that was the problem. I think the pond VOLUME is the issue. Too many fish for the gallonage of the pond is my guess, which created stress, which caused the fish to die. But it's only a guess.