Help advice with dying koi in outdoor pond

  • #1
Hello to all.
I bought by first koi in October 2008. And and a 3rd in or about sept 2009.
My 3rd, from sept 09 was found dead today.

I had them in a 65 gallon indoor tank, and moved them outside to a 200 gallon tank last summer. I then housed them inside till this may, and again, moved them outside.

I live in USA. NJ.. It has been hot in the last few weeks. My water temp did not see to be measuring over degrees, but I think my thermometer was off by about 5 degrees.

I noted a few weeks ago one of my koi, a white one, to look pinkish on the top or dorsal I believed its refered to fin. This is my 1st experience with koi or any fish.

I do have two pumps. a UV lamp and aerator in the pond. I only noted the one koi to look like this, and last year had no problems.

I thought due to the lack of (fake) lilly pads which I had last year, and the size increase from about 5 inches to about 10 now may be causing the sun to be to penatraiting to the koi.

I added salt. and a UV blue liquid to mask the sunlight from the pond, and also added shade to 25% of the pond. after two weeks the fish seemed to look better, and even thou one looked reddish. it did not seem the rest were eating much at all.

After the two weeks when the one started to look better the other one was starting to eat again. Then the tables turned back, within the next week. It was getting hotter like a small heat wave, but even with my now added UV and covering, I noted the same fish to look reddish again.

I don't not, but will get an ammonia test. I did other nirates, nitrates, PH, tests which were all in range and seemed ok.

Today by wife said she had saw the one fish swimming, but then she saw the fish later looking dead. She awoke me, and I confirmed he was (apparantly) dead. I am concerned now, aside from feeling hurt (these fish our a part of my daily come home and see life), sad, as I read on here that maybe I could have moved him back and forth and possible revived him.

The fish who is now deceased looked a little reddish on the edges of his fin, not on the fin and back like the photo I will put on my white one.

I am just wondering if it is not some type of sunburn, if it was a parasite which will kill my other fish. If the "antI pond mosquito puck thing" I added which said it was fish safe, I put that in 3 days ago, killed it. If the UV stuff was bad for them?

I am deeply saddened. I don't want to find the other two dead I got these fish
one for me, my wife, and one for my child. I have been looking at building a larger pond, etc but its sadly, as maybe you can understand, I don't know what to or, not to do.

Any suggestions are appreciated. I will add a photo of the one fish. Aside from the color, I don't see any legions or any other different markings, except say the area which is red is slightly inflamed. The other fish I have was always friendly, and this white one was more timid. But they all have seemed to huddle under the shade and not be eating the food I have been putting in.

Thank you in advance for any assistance you can offer.




platy ben
  • #2
Well the koi you have pictured certainly has sunburn, I have 5 white koi in my pond and all of them have had sun burn this year but mine are fine now.

I would say moving them about so much wouldn't have done them any good at all. Why did you move them back inside after you put them in the pond?

If you are considering building a pond I would advise digging your own one.
Here is a link to a thread of mine with a few pics of my outdoor pond

Just reading over your post again, I don't think adding salt would have been the best thing to have done either

Finally, Welcome to Fishlore!
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  • #3
my answers

initially I had them indoor in an aquarium. I moved them outside and and when winter was approaching I was concerned with them surviving in the winter. I read about just running a heater but wondered if it was best at there young and new age. I was not sure if I just shut down the air and filter, and toss in a heater and stop feeding and call it a day so to speak. So I brought them in.

I felt it wrong to keep them inside and was planning on making them full time outdoor now. So I moved them out. 3 months ago. I pumped the water from inside to the outside pond and therefor kept the water the same balance. which I theorized would change as the season evolved with them.

I did dig down 3 feet with the current pond being 18 inches above ground. 4.5 total depth. I wanted to buy a portion of lot behind my home now about 20 feet by 30 to dig a larger 1 or 2 thousand gallon pond. but as of yet only the lot research, and desire portion of that plan have been done.

I'm sure salt might irritate the burn., but if it was some parasite I only thought the salt might help with an infection as, like I said, even my dark black one seemed to be lethargic and he was the friendly eat from my hand one since the day I got him.
Nick G
  • #4
HI Wiley, Welcome to Fishlore! Theres no need to bring Koi indoors for the winter. Koi are just Carp, who will be fine in water during the winter, even if the pond freezes over. I used to float footballs in the pond during winter, that can be pulled out if the surface freezes, allowing the fish to surface if they want.
  • #5
Hello Wiley and Welcome to Fish Lore!

I hope you enjoy the site.

So sorry to hear about your fish. Here is a link that you may find helpful:

I'm sure you'll get more responses. Best of luck and please keep us posted.


I have moved your thread to the Pond/Koi section of the forum to help you to receive more responses from other members.
  • #6
Koi and Goldfish both can become lethargic during the hottest parts of the day. In the summer, my goldfish spend a good part of the day at the bottom of the pond under my lily plant where it is shady and cool. I have two rock shelves and two pvc pipe caves that they also use as shade. I go out to feed them in the early mornings or late evenings when the sun is off the pond and the water is a bit cooler. They are more active then and will come right up to be fed. It is hard to have plants with koi, since they love to eat them. If you can get it, water lettuce is a floating plant that is fairly hardy and will help shade the pond. Also, is the only water movement the little pipe thing? Having more water movement - a larger waterfall or a bubbler type fountain - will help to keep the water a bit cooler and more oxygenated. Warm water does not hold as much oxygen and your fish could have died from a combination of sunburn and lack of oxygen.

To try to answer some of your concerns -
Salt is not really needed, but can be helpful depending on your water. I use it as a salt dip in another container if any of my fish get parasites or something.
A UV bulb is excellent (in my opinion) because it prevents the 'green pea soup' algae bloom that can happen every summer.
The UV blue liquid doesn't really do all that much to prevent sunburn on fish because the fish swim at different levels in the water. If there is not enough oxygen in the water, then the fish will swim at the surface where there is a higher concentration of oxygen and less protection from the sun. Floating plants to cover about half of the surface of the pond is much better. Also the plants will help to use up the nitrates in the water and help to keep your pond healthier. Floating plants are harder for your koi to eat since their leaves are more above the water.
The mosquito dunk (the round donut looking thing you drop in to kill mosquito larvae) is okay, but not really needed. Contact your local extension service and tell them you have a decorative water feature and you would like to know if they have any Mosquito Fish. Most states will supply you with some to control mosquito population. The Koi may eat some of the very young ones, but generally ignore them once they are about 1/2 inch long. Mosquito Fish devour mosquito larvae and will also eat adult mosquitos that come to lay eggs. I have seen mine actually jump out of the water to catch mosquitos. They are pretty good at it. If you have floating plants (such as water lettuce) the roots of the plants will provide ample hiding places for the mosquito fish and their young.
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  • #7
Todays status

Well its seems today I found my 2nd (my 1st bought koi) gasping and being listless.
I checked the pond water. I did feel that Ammonia was the cause. Seems to have a high level around 4.0ppm. I removed them to a 1/2 mix of origional water and then a cleaner mix.
The origninal water was a high ph around 7.4 which might have kept them to bay this long???

I added the two remaining to a holding tank with double aeration, (occasional shots of 36% nitrox from my scuba an extra 15% oxygen in the water).

I added more biological booster to drop the ammonia.

The tank levels are , Ammonia 0.5ppm, PH higher around 7.6, neg on nitrates, and nirate.

seemly my fish was found about 5 hours later on the bottom upside down. He tend when I let him go to pitch upside down and roll to the bottom of the tank and lay there listless.

I think if the ammonia caused a breathing gill problem that maybe there is just to much damage to help him?

I did a few tug backs and held him over the aeration and tank inlet areations to hope the flow would more motivate him to at least stay upright, but it seems I am fighting a losing battle.

I cannot say why this got this way, other to say maybe my neglect to manage the ammonia checking more frequently. I did add bio booster a few weeks ago which was supposed to help to boost turning the ammonia to ammonuium, and help negate any problems.

When there were inside, I had kept a constant change of zeolight/carbon mix. to kept taht at bay, but last year there was not used that outside, so maybe a loss of that with the failure to bio boost the tank outside is the cause.

I moved them out and pumped the tankw ith the current indoor tank water, but maybe I shoudl have bio boosted the outside tank two montsh about rather than a few weeks ago?

Any input is helpful... Ill let you know f any positive changes occur.
My remaining fish was noted to also have the pinking gills and that leads me to think aside from sunburn on the top, that ammonia may have led to a gill condition?
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  • #8
So far when I left tonight my fish was still "alive". He was on the bottom still lying upside down, and visibly "puckering" for breath lying on/next to the air stone.

The water (even though I have a 1800 GPH pump in a 200 Gallon tank) with the two koi in it, seemed cloudy (white cloudy).

I could see by the tail area of the koi that there looked to be some white material (like wet powder looking). Not sure if that is some type of discharge.

I have been reading that "dropping a fish" can lead to swin bladder problems. He was dropped when we moved him 3 months ago, but with the other fish dying yesturday, and him upside down like a sinking submarine, I don't think this it the issue.

Its killing me, that I really cannot figure out if something is still "killing" it/them. Of if the possible high Ammonia levels would cause this to be a losing proposition.

I am curious to what the white substance it. But I did not have the time to look as I was late to work, from being up all day trying to support my dying Buddie.
  • #9
Look at the picture below and see if that is what the "white stuff" looks like. If so, it is from the sunburn. Sunburn damage can heal - Melafix is a good medication for wounded goldies (and koi). From what I have read, it seems that Koi are more susceptible to ammonia poisoning than goldfish. If there is too much damage from the ammonia, the Koi may not heal. All you can do is keep the koi in water with no ammonia - which means daily water changes of about 50% with a water conditioner such as Prime or Amquel+. Prime and Amquel+ make the ammonia in the water "safe" for 24 hours - until your next water change. Gasping and staying close to the bubbles are signs of ammonia poisoning.

Here is a picture of one of my goldfish that got sunburned. It almost looks like cooked fish - white and flaky. The damaged tissue will turn black as it heals. (the fish in this picture has completely healed and shows no scars.)


  • 04-15-07_1305 sunburned goldfish.JPG
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  • #10
its hard to say. I want not able to see that much in the few seconds I had to look. but it appeared to be settled on the bottom of the tank with the fish.
Would the ammonia poisoning lead to the fish laying on its back. Seems like he has ammonia and also that swin bladder issue all developed within a few days.
I'm stuck working overtime, and I will update when I can get home an assess where I'm at. hopefully he will be alive and better. time will tell.
  • #11
Good morning,

I have removed the link to the video that you had posted since it had been blocked by the owner of the video due to copyright issues.

  • #12
Ammonia poisoning can take weeks to show. By all that you have posted so far I would say that ammonia poisoning is/was your problem, even though the water checks good now.

I had that exact same problem years ago with my first Koi pond. Nearly all my Koi died over a period of 3 weeks!! It was to the point that I was afraid to check the pool for fear of another dead fish.

I do not use a UV lamp. Every spring I get the "pea soup algae" and it is an indicator to start some water changes....too much nutrients...and the filter hasn't ramped up yet from the winter.

During HOT summers like we are now having I add a monster airstone to help move more water...I use an Alita Air pump.
  • Thread Starter
  • #13
Todays update. My Koi is still "alive"' More so lying listless on the bottom on its side, by the airstone breathing away.

The white reside seems to have broken down. and I'm left with some "cloudy" water slightly and there was a foamy reside on the top of the tank this morning.

I am wondering if I should seek adding anything to the tank. Like salt or maybe some helpful remedy?

I can't help but wonder if some parasite may just be slowly killing my fish and that is is suffering, as opposed to the thought that "Now I have him in better quality closely monitored water and in time he will feel better"'.

The other fish in the same tank is still swimming and I have yet to better assess its physical condition. I worked a double and came home exhausted. and Getting up tonight I did not have the lighting conditions of time to better assess it.

Any recommendations?
  • #14
I don't think you are dealing with a parasite - I think it is a combination of the sunburn and the ammonia poisoning. The koi's gills have been burned by the ammonia which is making it hurt for the fish to breathe. Throwing a bunch of different parasite medications in there may just make matters worse. Salt, too, is an irritant that could hurt more than help at this point. Melafix is the only medication I would recommend at this time. It will help with the burns, and may help some with the ammonia burns, but the best thing right now is clean clear water. Even if that means daily 50% water changes. Think of it this way - have you ever had a really really bad sunburn? Or any other type of burn? Remember how it stings and hurts when you get water on it? Every time your koi takes a breath, it is like pouring water on that burn - it stings and hurts. It will take time for it to heal, but if the burns are not too bad and if you can keep the water cool and clean, your koi should heal.
  • Thread Starter
  • #15
Another update

I spent the last two days getting advice from a major , exclusive fish store, 16,000 gallons of fish and exclusive koi sales. As well as a lady from petco.

I decided to add a little salt the other day, but since I see the benifits of it as more so to build a slime coat and thus protect the fish, I'm not going with that right now. I also see that if the fish has a residual burn condition the salt will probably cause more of an issue right now.

I did pick up "API Triple Sulfa". It seems the most recommended med to work with to treat, pre treat, and deal with an array of conditions.

In addition I added a product called "coppersafe", which was more aimed towards any ick conditions.

I will add two photos. One from two weeks ago and the other today.
As you will see the major black sides of the koi, are now more orange, which was a base color of him on the bottom.

I did more extensive testing and feel some issues at the start were:

1. When I moved them outside, I transfered them from a indoor tank water, to outdoor. I had NOT rebuilt the outside ecosytem/filter/bateria colony.

As I have been doing water changes the last 3 months I have been using a dechlorinate product, and water tests shoe my incoming water as NO chlorine.

2. As I have been adding water, I have actually been adding ammonia, as my incoming water does test about 0.50 for ammonia.

So in essence I am thinking the lack of the built up ecosystem would contribute to the ammonia not being transferred to ammonium in an adequate time. And leading to a gill burn condition.

Whereas the koi was as time coming to the surface by the fountain is was only occasional , and he did tend to hid more towards the last week of his being sick which was an early indicator if I had check then, the ammonia, that it may have been an issue.

As for the other koi, herein pictured above, the "white one", he went from being red, to all white again and then two days later, after total cover from sun, I saw the red streaks which led me to think that maybe a parasitic conditions does exist. You will also see todays photo of the current appearance and the color change of the black koi.

I will look into the "melafix". As of the last two days one of treatment, I have noted the fish to go from a rapid breathing to a shallow and now back to a slightly more rapid condition.

The one white fish when I can to add the treatment of Triple Sulfa, was jumpy and actually jumped and hit the side of the tank. He then shuttered, and went listless to the bottom of the tank....I was like "great, he just broke his neck and died". I realized it seemed he knocked himself unconscious.

Well the daily water changes are about 25% now with the sulfa treatment for the next 3 more days and I will see what I can assess then. I am glad my koi is still alive and has not perished, but if it looks like its suffering I would rather release him into a viking funeral

Two weeks ago:




Made note of the "scrape/legion on the head above the left eye area)


Koi right side: Gills don't look red on interior like am ammonia burn... the white fish had pinker looking girls, but maybe the flesh color causing me to think less burn looking?

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