Welcome to Koi Forum. Is this your first visit? Register
Results 1 to 14 of 14

Thread: Koi Death

  1. #1

    Koi Death

    Hi,
    I have an urgent situation in that I have a Number of large Koi showing symptoms of lethargy and lost appetite.

    I own a pond which was formally a swimming pool, it has a 10,000 gallon volume, with 12 Koi, 4 Golden Orfe and 50ish Goldfish. I have equiped the pond with Pump, filtration and a skimmer.

    Water quality tests all show normal.

    I have had no fish health problems for several years. Then several weeks ago one one of the mature Koi exhibited symptoms of lethargy and lost appetite.
    I dosed the Pond with TAP Formalachite, but this did not appear to resolved the problem, the Koi did start to regain his appetite however, so I thought it must be the hot weather. Then a second Koi started to exhibit similar symptoms, only more severely. And within 10 days the second Koi died unexpectedly. Examining the fish postmortem it appeared to be in excellent condition with no outward signs of a problem.
    I have a microscope and quarantine tank on order which I hope will reveal some form of treatable parasite, however, tonight at feeding time I noticed several other Koi exhibiting similar symptoms, and judging by the rapid deterioration of the second fish I'm concerned that I may not be able to diagnose and treat in time. Could anyone suggest an emergency course of action, that I could take as an interim action.
    Thanks!



  2. #2
    Moderator Rank = Supreme Champion Feline's Avatar
    Join Date
    Aug 2013
    Location
    Somerset
    Posts
    6,653
    Thanks / Likes
    5635
    Your emergency course of action needs to be to do some scrapes to get a diagnosis.
    You simply cannot safely treat an unknown problem.

    If I was faced with impending fish losses and couldn't do the scrapes immediately (or get someone in to do them for me) then I would add as much air as I possibly could to the pond and do an immediate 25% water change with dechlorinated tap water. But scrapes are urgent here.

    I think it would be worth you posting up your actual water test results here too if you want meaningful advice ('normal' is meaningless unless we know what you think normal is and know what you have tested for and with).

  3. Thanks freddyboy, Manky Sanke Thanked / Liked this Post
  4. #3
    Hi Feline thanks for you quick response and advice,
    The water test result showed zero, on ammonia, nitrate and nitrite, PH is 8 which is normal for this area and my pond, I don't have a KH value.
    I'm hoping my microscope arrives tomorrow so I can do the scrape samples which hopefully will identify the problem. In the mean time I will do a partial water change and aerate as much as possible.

    Thanks.............

  5. Thanks freddyboy Thanked / Liked this Post
  6. #4
    Moderator Rank = Supreme Champion Feline's Avatar
    Join Date
    Aug 2013
    Location
    Somerset
    Posts
    6,653
    Thanks / Likes
    5635
    Quote Originally Posted by Normsmeboy View Post
    Hi Feline thanks for you quick response and advice,
    The water test result showed zero, on ammonia, nitrate and nitrite, PH is 8 which is normal for this area and my pond, I don't have a KH value.
    I'm hoping my microscope arrives tomorrow so I can do the scrape samples which hopefully will identify the problem. In the mean time I will do a partial water change and aerate as much as possible.

    Thanks.............
    Great, let us know how you get on.

    Just a quick question- how are you dechlorinating your top ups? Is there any chance chlorine could have been getting through? If in doubt pour some extra dechlor in the pond as a precaution since it won't hurt anyway.

  7. Thanks freddyboy Thanked / Liked this Post
  8. #5
    I tend to use a fine spray on a garden hose, not ideal I know but, i reckon that the volume of the pond is such that the slow introduction of water in this way should keep chlorine to minimal levels, at least this method has never caused issues in the past. Most of the water added in recent times has been rain water, so no chlorinated tap water for some time.

  9. #6
    Moderator Rank = Supreme Champion Feline's Avatar
    Join Date
    Aug 2013
    Location
    Somerset
    Posts
    6,653
    Thanks / Likes
    5635
    Quote Originally Posted by Normsmeboy View Post
    I tend to use a fine spray on a garden hose, not ideal I know but, i reckon that the volume of the pond is such that the slow introduction of water in this way should keep chlorine to minimal levels, at least this method has never caused issues in the past. Most of the water added in recent times has been rain water, so no chlorinated tap water for some time.
    Chloramines can never be gassed off and last a long time in the water- it's extremely risky to rely on dilution alone to save you here. All it takes is the water board to do a pipe flush during repairs or maintenance locally and your fish will be at risk of death using that method.

    Topping up with rain water only puts you at severe risk of pH crash, particularly if you cannot even test for KH.

    From what you've said I think an emergency water change would be a really good idea- but you MUST dechlorinate that tap water properly. Keep a sample of pond water from before you change it too much and order a KH kit so you can check retrospectively what was going on.

  10. Thanks freddyboy, Manky Sanke Thanked / Liked this Post
  11. #7
    Hi, Sorry for the delay, I've been working on the problem. I have a new test kit and all parameters including KH and GH are good. I bought some sodium thiosulphate and treated the pond whilst replace 25% of the pond water (3,000ish gallons) I also bought a decent microscope (ouch!) and discovered skin flukes. Bought some Fluke P (ouch again!) and treated the pond. I've also been aerating as much as possible. The original Koi that was hovering on the surface and lethargic disappeared the day after treatment and haven't seen it for 3 days (somewhere on the bottom!).
    Slightly smaller Koi acting strange now with one gill closed and the adjacent pectoral fin not working properly, not eating and lethargic. Almost all fish diving to the depths apart from meal time, don't know how much this has to do with all the disruption or not, now playing the waiting game. Planning to do another scrape tomorrow on the dodgy Koi to see if there are any signs of skin fluke or other parasites.
    Any observations, advice greatly appreciated.

  12. Thanks freddyboy Thanked / Liked this Post
  13. #8
    Extreme Koi Member Rank = Mature Champion pip895's Avatar
    Join Date
    Nov 2013
    Location
    Nr Farnham, Surrey
    Posts
    2,069
    Thanks / Likes
    831
    How is it going? My concern for you is that I think the flukes are a side issue - they multiply when fish are knocked back by something else, they can cause irritation to the fish but don't generally cause the symptoms you discribe.

    How clear is your pond of debris etc. This might be a bacterial issue in which case pond cleanliness is important. I would consider reducing feed as well until you get on top of the issue. - Which ammonia test kit do you use and what were the actual values?

    You have a seriously big pond there - what filtration do you have on it?
    6000g in ground koi pond
    +3000g lily/Anoxic pond attached
    29 koi (40 to 65cm)
    Bottom drain, Mid water & Skimmer to Drum
    JBR boichamber->Blue eco 500 pump ->below surface return.
    Blue Eco 240 -> Large MB -> Waterfall -> Planted Anoxic pond (25 baskets)

  14. Thanks freddyboy Thanked / Liked this Post
  15. #9
    Hi PIP,
    Thanks for the response,
    Yes it is a large pond, it used to be a swimming pool!
    Pond Update......
    Unfortunately I lost the original Koi (the first to show symptoms). However the Fluke P seems to have made a difference in that there are no new cases. Having said that, there is still one of the larger koi's that is still lethargic and is not eating. I thought this may be simply be part of the recovery process, though having waited a couple of weeks (post treatment) he doesn't seem to be improving or for that matter getting worse.
    So I removed him and took another scrape. There was no sign of skin flukes, but there is trichodena which probably explains why most of the fish have a suppressed appetite and are acting a bit skittish. So i have ordered PP and HP to treat the trichodena.
    To test the pond water, I used a new test kit, the NTLabs Aquarium Lab. This uses a colour scale, and my pond water registered yellow which apparently equates to zero ammonia.
    My Pond filter is the Oase Screenmatic 36 with an in-line twin 55 watt UV.

    I should get the PP in the next day or so. So I can give an update next week.

  16. Thanks freddyboy Thanked / Liked this Post
  17. #10
    PP arrived and have dosed the pond. I recalculated the pond volume, not easy to do but my revised estimate is 12,000 gallons.
    As such the dose used was 80 grams based on 6.8 grams/1000 gallons. I was expecting the water to look pinkish or purplish, but it didn’t. I wondered whether this was due to the suspend algae in the water.
    Due to suspended algae I decided to increase the PP dose another by a further 40 grams, with hydrogen peroxide on standby. The fish did not seem to be troubled, I say “seem” because they were no where to be seen with the commotion caused during the PP dosing.
    Incidentally, the water still did not appear to take on a pinkish hue?
    so not sure if I have achieved anything, I will take another scrape and see what I find and let you know.

  18. #11
    Moderator Rank = Supreme Champion Feline's Avatar
    Join Date
    Aug 2013
    Location
    Somerset
    Posts
    6,653
    Thanks / Likes
    5635
    Quote Originally Posted by Normsmeboy View Post
    PP arrived and have dosed the pond. I recalculated the pond volume, not easy to do but my revised estimate is 12,000 gallons.
    As such the dose used was 80 grams based on 6.8 grams/1000 gallons. I was expecting the water to look pinkish or purplish, but it didn’t. I wondered whether this was due to the suspend algae in the water.
    Due to suspended algae I decided to increase the PP dose another by a further 40 grams, with hydrogen peroxide on standby. The fish did not seem to be troubled, I say “seem” because they were no where to be seen with the commotion caused during the PP dosing.
    Incidentally, the water still did not appear to take on a pinkish hue?
    so not sure if I have achieved anything, I will take another scrape and see what I find and let you know.
    The best and safest way to use PP is to use a redox meter, and rather than guess pond volume, organic load and ‘purpleness’ you just dose to keep at 450 mV for 4 hours, topping uo whenever necessary to keep it there.

  19. #12
    Thanks Feline,
    great advice, can you recommend a redox meter? Done some searching and am struggling to find something that I would have faith in without breaking the bank.
    Thanks again

  20. Thanks freddyboy Thanked / Liked this Post
  21. #13
    Moderator Rank = Supreme Champion Feline's Avatar
    Join Date
    Aug 2013
    Location
    Somerset
    Posts
    6,653
    Thanks / Likes
    5635
    Some of the really really cheap pen type ORP meters are a bit shoddy and don't last very long. I think my first one cost me £12 but only worked twice

    I've now got one of these https://www.amazon.co.uk/HM-Digital-...ds=redox+meter
    For a mid-priced one it is not at all bad and can be calibrated.

  22. Thanks freddyboy Thanked / Liked this Post
  23. #14
    Thanks feline, yes I did see this one but wasn’t sure. So You’ve helped make up my mind��

  24. Thanks freddyboy Thanked / Liked this Post
 

 

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
All times are GMT +1. The time now is 04:39 PM. Online Koi Mag Forum
Powered by vBulletin® Version 4.2.3
Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.

vBulletin Improved By vBFoster® (Lite Version), © UltimateScheme, Ltd.