Please help save my fish from this mass death mystery

[Charles2465]

I'm reaching out in desperation about my fresh water pond because I don't know where else to look.
Over the past week I've lost a lot of my koi due to a pump electrocuting them, after that I put in the spare pump to try save the remaining fish. It also seized so I had to resort to using airstones to keep them from suffocating. The pump took 3 days to arrive and no fish had died yet but they did not want to eat. I installed the new pump and did a water change. The next day one of the larger koi died, found him dead at the bottom of the pond. I thought there was a spike in nutrients and when I started the pump and filters up again it stirred up debrie and caused it to worsen. I did another waterchange. Another koi died displaying symptoms of just not having balance and no energy. After the water change another koi died the following day. It even responded to me fishing it out with the net it seemed to have sufficient energy but had no balance. Now a day later the goldfish is doing the same thing and I have no idea why.

I've never experienced something like this before, ph is fine, ammonia is fine and the nitrites. Any help will be much appreciated.
Also side info I dosed the pond with some medicine, fungus clear(followed all the instructions) and the amount of that in the water will probably be close to none but I though I just add it in because I'm lost at this point.

 

[ying yang]

Never had ponds so wouldnt like to give you bad information but will bump this upto top question as some have reefs and freshwater tanks and some have ponds.
Not sure when you added the medication but is it possible that medication took alot the oxygen out the water and with no pump circulating water and surface agitation the oxygen went down further and bigger fish need more oxygen so they died first ?
Seems like a few problems all cascading into other problems.
Electruction in ponds from pump not sure how that works fully tbh.and detritus stirring up and meds then fish get stressed then wont eat then get more sick.and possible try feed more so then pollutes water more ?
I wish you best of luck in whatever you decide.
I know sometimes water changes are needed but sonetimes they can be detrimental if change to much,to often.

 

[Charles2465]

Never had ponds so wouldnt like to give you bad information but will bump this upto top question as some have reefs and freshwater tanks and some have ponds.
Not sure when you added the medication but is it possible that medication took alot the oxygen out the water and with no pump circulating water and surface agitation the oxygen went down further and bigger fish need more oxygen so they died first ?
Seems like a few problems all cascading into other problems.
Electruction in ponds from pump not sure how that works fully tbh.and detritus stirring up and meds then fish get stressed then wont eat then get more sick.and possible try feed more so then pollutes warer more ?
I wish you best of luck in whatever you decide.
I know sometimes water changes are needed but sonetimes they can be detrimental if change to much,to often.

Thank you for your reply and regards.
I did have some air pumps keep the oxygen levels up while there was no pump, but they all started dying after I installed the pump, so I don't think it is oxygen.
The pump that electrocuted my fish seized and then the power used to power it just went into shocking the fish, electrocution is rather rare but I think what made it severe was because the pump had metal housing making it more conductive. I did smaller water changes so I'm not sure if it's that.

 

[Charles2465]

I just had my water tested for for everything at the shop. It appears there might be a combination of things. It's possible that there was a spike in nutrients. What showed in the test is that there was a large amount of minerals in the water. I'm not sure if the pump causes electrolysis of some kind and made something toxic. I usually add some salt to keep their skin healthy and there could be impurities. I think that was the problem

 

[ying yang]

Well hopefully you get to bottom of it.
I know in fishtanks if never ever disturb the substrate then one time you decide to disturb it then all that nastiness in the sand/ gravel all gets released into the water at once and can kill fish.maybe with your pumps coming on and off as replacing replicated this idk.
But would thought koi carp quite large and would be disturbing the substrate regulary.
I will bump this to top of questions again to see if someone who experienced in ponds and reefs sees it

 

[Huskymaniac]

Is it possible you got a contaminate in the pond?

 

[ying yang]

And also on your water change did you use tap water? And if so did you remember to use a declorinator? I guess same as in fishtanks as chlorine/ chooranomine in tap water kills all the bacteria etc making it safe for human consumption but not for our beneficial bacteria in fishtanks.so guessing it same principle in ponds ?

 

[Charles2465]

Yes I did use declorinator
I believe the problem was related to some chemicals in the water as the total dissolved were very high.

 

[Charles2465]

Could the pump that failed be related to it?
I opened it up and the plastic was melted inside. Does this mean the melted plastic released chemicals that slowly killed my fish?

 

[dedragon]

Could the pump that failed be related to it?
I opened it up and the plastic was melted inside. Does this mean the melted plastic released chemicals that slowly killed my fish?

Its definitely possible that it released stuff from burning. using carbon and water changes should translate well to ponds, sorry havent had a pond before but do have both fresh and saltwater tanks

 

[Charles2465]

Hi guys I just wanted to thank you all for trying your best to help.

I did some more research and found a person that had the same incident. Their pump seized and stopped working and the plastic and what-not melted inside. Same as him people could not find a definite answer and could only speculate. All his fish died overnight.
It appears his was more aggressive than mine but it was ultimately the same result minus the 2 surviors I have that may or may not make it. It seems fitting to call it Pump nuke.
I have been doing quite a few water changes and their behavior seems to be improving. I got my water tested today and the TDS(total dissolved solids) have come down to 480 from the original 600+.
I plan to keep doing so until the TDS is back to normal and then I will go from there.
Thank fully I did get to the bottom of it and sooner or later I should be enjoying my pond again.

 

[ying yang]

Thanks for reply on outcome for you.always good to know what problem or most likely cause is and could help others reading this thread in coming months/ years to come.anyway good luck and hopefully you get more enjoyment than problems out of your pond to come ^_^