Help ! Something in my pond keeps killing my fish.

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Can anyone please help me, I have had my Koi pond for 5 years and no problems at all. Last year we bought some plants from a garden centre and with a couple of weeks we lost all of our fish within 2 days. I emptied the whole pond power hosed it and started again. I even bought all new gear pump etc. as I did not know what caused it. I then waited 2 months and bought of fish to try and with a week they died too, so again I emptied the whole pond scrubbed it and all the equipment and started again adding all the stuff to get it going again and left it. Last week I was given some fish as they had to be re-homed so stuck them in...... Today they are dead. My wife has noticed these growths on the pond could anyone helps please
pond1.jpg
pond2.jpg
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addy1

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Not sure about the growths. Do they feel slimy, if you pull one off it is algae, a bug, snail eggs?

Have you done any water tests? I killed off fish when I first built my pond, our well water had a ph of 5.3, deadly to fish.

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With as many times as you've restarted, I don't think there's anything IN the pond killing them, other than perhaps the actual water. I'm with @addy1 - test your pH.

A few other questions - you said "koi pond". How many gallons is your pond? It appears to be a preformed pond - you won't find a preform that's big enough to keep koi. While it may work for a time, the fish will eventually outgrow it. How many fish did you have or are you adding at one time in the pond? What kind of filtration? What's your water source - i.e., well water, city water, etc. Did you add chemicals to the pond to control algae or sludge? What did the fish look like before and after they died - any symptoms like gasping or fins clamped or laying on the bottom?

As much information as you can share will be very helpful going forward. We have lots of smart folks here who can help sort the problem out!
 
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You should really test more than the pH. Get the liquid testing kits for pH, ammonia, nitrite and nitrate, and KH. Most of those come in the API Master Test Kit. The KH kit is sold separately. Don't use the strips. Those are inaccurate so they really pretty useless.

Scrubbing down the pond and replacing all the equipment is not the best idea, unless you know for certain that you have introduced a disease. You eliminated any beneficial bacteria you might have had by doing that. Please read about the nitrogen cycle and how it works, if you are not familiar with that.

Also leaving the pond empty and running won't do anything but circulate the water. It needs a source of ammonia to start cycling.

Like others, I feel this is a water quality problem so that has to be fixed before doing anything else.
 

sissy

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Number one is always clean plants and roots well and never put them straight in the pond .I always wait 2 to 4 weeks before they go in and I really inspect the roots of the plants .I agree you really need to let the pond mature and get a liquid test kit .Chemicals never really help the problem and can only add to it .Do you have an aerator .How big is the pond and seems like it must be a preformed .Rain can also wash chemicals from your lawn into the pond .
 

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1579708127181.gif
@LeeB
Are you using tap water and does it contain chlorine/chloromine? If so you need to add drops to get rid of these as you fill your pond. W/o treating to rid these chemicals it will kill your fish fast. Those things on your liner look like snail eggs and they would not be killing your fish like that.
 
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The lumps are almost certainly snail eggs. Snails can be a stage host for parasites but it's pretty rare, and black spot disease is extremely rare. Probably a chlorine kill, or lost biological filtration
 
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Welcome to the forum, but sorry for the loss of your fish. I agree with the others, test your water for various criteria ( PH, KH, ammonia, nitrite and nitrate) and share the results with us.
 

Mmathis

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Hello, and sorry to hear about your problems....

Agree that it sounds like a water issue. As someone has already asked, how large is your pond? How many fish have you been keeping? What kind of filtration do you use?
 
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Can anyone please help me, I have had my Koi pond for 5 years and no problems at all. Last year we bought some plants from a garden centre and with a couple of weeks we lost all of our fish within 2 days. I emptied the whole pond power hosed it and started again. I even bought all new gear pump etc. as I did not know what caused it. I then waited 2 months and bought of fish to try and with a week they died too, so again I emptied the whole pond scrubbed it and all the equipment and started again adding all the stuff to get it going again and left it. Last week I was given some fish as they had to be re-homed so stuck them in...... Today they are dead. My wife has noticed these growths on the pond could anyone helps pleaseView attachment 126036View attachment 126037.
 
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Welcome!
This really sounds like a water quality thing but if you had a Koi pond for 5 years without problems I would check the water quality first before repeatedly scrubbing everything down. Did something change? Well or tap water? If tap, did your municipality start adding something different to your water, other than the usual chlorine you know you have to get rid of? I'd call the water company. If well water, was there a change in environment, as in runoff?
Did you get any new types of plants? What medium are they in? Rinse them real well before putting them in.
When you want to try fish again I would throw in some feeder gold fish. Nothing expensive. If they survive for awhile then I'd set up my balanced echo system. I don't know your pond size, but one Koi requires 1000 gallons. If you had a Koi pond for 5 years you must have been doing something right. This really sounds like a chemical additive to me.
Good luck and let us know. My curiosity level is over the top. We lost fish as well, but my husband added too much algicide one summer. Any amount is too much to me.
 
S

sheribe

First off, depending on the size of your koi, a preformed pond will work for a time until they get larger. I had mine in a preformed pond for 3 - 4 years before I enlarged to a liner pond as I knew the preformed was not large enough as they were growing. Last summer, I lost 5 of my 6 koi, 3 I had since 2015 after I had lost my previous ones to debris falling into my pond from Hurricane Rita. It sucked all the oxygen out of the pond. 2 of the koi lost were babies of the 3 I had replaced with ni 2015. We could not determine what was causing the problem for them to die. When the first one started acting weird, swimming on it's side, holding it's mouth open, not gasping as such. I tested and the water was fine, pH, ammonia, nitrate, nitrites, etc. After it died we drained the pond anyway put in fresh well water, all levels were fine. then about a week later the other 4 started slowly doing the same things, swimming on their sides and keeping their mouths wide open. The only thing we could come up with was we had sprayed for Crazy Ants near the pond and a bunch of them had either fallen into the pond or the living ones had put the dead ones in the pond, thus the fish eating them when they ate their floating food. the chemical we used causes neurological problems in the ants so we figured that was what happened with the koi. I had inspected them, nothing caught in their throats, no parasites, nothing wrong with gills or fins. all looked fine. some how one of the smaller koi managed to live and has made it since mide summer and it is February. I hope to get more koi in the next few months as it looks lonely swimming in 1400 gallons all along. I also do have small snails in my pond and have had them forever along with a few plants that I have had for many years. Good Luck and I hope you find your problem.
 
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Ich can travel on plants, and the newer strains of ich are very difficult to clear up. They don't respond to formalin and malachite green. They just kind of laugh at older meds and keep on infecting new fish. Saltwater dip fails to knock ich off, it's become similar to marine ich on regal tangs, imbeds in a deep skin layer and re-occurs months later. I wouldn't replace all equipment after a mysterious fish kill but I'd sure clean hard including a wipe down with bleach and allowing all surfaces to dry thoroughly before refilling.
 

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