Devastated, lost most of my pond goldfish

[bettasngoldfish]

I need some help here trying to figure out what happened to the fish in my pond that made them die I have kept fish for many years (although most of the time has been in aquariums) I have had fish die but never what I just experienced with my pond goldfish. I have had the pond for about 5-6 years now (some of the fish have been with me since the beginning others were added or born in the pond) I had a total of 14 or 15 fish ranging from very tiny to 7-8 inches (maybe a tad larger it's hard to tell without actually getting the measuring stick out)

I believe as of this morning I have one large goldfish (Shamu who was one of my first pond fish) left (saw her swimming around the bottom of the pond) and possibly one smaller baby left (I couldn't find it when I went out to take a look this morning before work, it could very well be dead)

I was playing around with my camera taking video in the pond the day after my routine water change and everyone looked happy and healthy to me.

I have no idea what caused this sudden death. My fish were fine one day (or so I thought) and then dead the next (over a two day period I lost a total of 12 fish) Filter was cleaned last month, water change was done July 25th (a little less than 50%) we had a heavy rain the following weekend on Sunday night then Monday after work is when I started to find the bodies (total of 2) Tuesday I found several more bodies and did water tests which I thought were fine. Wednesday I did another large water change and found more dead fish. I have no idea if the heavy rain had anything to do with the deaths but just wanted to mention it. No run off that I know of as pond edges are slightly raised.


Temperature in the pond has been in the low 70s, fish have been eating normally (I feed them 4-5 days a week) none of the fish have been showing any odd behavior. Pond is mostly shaded, filter running 24/7 with small waterfall as well as 4 air stones.


Test results:

Ammonia 0, Nitrite 0, ph 8.7, gh 60, kh 80, phosphate .5, nitrate 0 (all tests are liquid drop test with the exception of the ph which is an electronic meter) I'm unsure if any of these numbers reveal any trouble with my water so I sure could use some advice. I do have to say that the gh and kh test kit was expired this past January so I'm not totally sure how accurate they are (I placed an order to replace it)

Any and all advice welcome

 

[tbendl]

I would say it was the water change, if your test results are normal then that's the only thing that seems to have changed.
I'm so sorry Maria, hopefully someone with more experience will weigh in. I hope the remaining fish make it.

 

[MitchM]

Very sorry to hear, Maria.
Did you treat your supply water for the water change?
Sometimes municipalities will treat the water supply with extra chemicals to counteract the extra pollutants brought in from heavy rainfalls.

Also, did you noticed any unusual algae growth in the pond shortly before the deaths?

.

 

[bettasngoldfish]

thanks guys

I used Aquasafe for water change dosed at total pond volume (as I usually do)

I have done water changes with the same water and conditioner in the aquariums recently with no issues.

No unusual algae or anything that I can think of.....

 

[bettasngoldfish]

IF I did happen to forget to use the water conditioner would it take up to 7-10 days to kill the fish?

Now I'm second guessing everything......

 

[Meyer Jordan]

Obviously something changed in your pond's water drastically and abruptly. My first thought echoes what has already been suggested...the water changes. Why such large water changes (50%) that often (2 weeks)?

 

[bettasngoldfish]

I have always done 50-75% water changes on my goldfish tanks every 1-2 weeks so it is something that I have continued with the pond (although I don't do them as often on the pond, I would say maybe once a month) the only reason I did two in such a short time was because of the deaths. I wanted to change out some water in case there was something in it that I wasn't testing for that was causing the fish to die.

I would also like to add that after finding the first two dead fish I did notice that some of the others were hanging out more at the pond surface and were lethargic (not swimming rapidly away from me as I netted the pond and moved some of the floating plants) but again these symptoms were only something that I was seeing after starting to find the first dead fish (again they have all died within 2-3 days)

And just to clear up the time line the water change was done on one weekend and then the next weekend we had a very heavy rainfall. The next day was when I started to have fish dying. So it didn't happen immediately after a large water change.

 

[MitchM]

I don't do large water changes unless there is an emergency.
Especially with municipal supply, you never know if there is maintenance being done on the water system and some parameters have been drastically changed. Maybe even some sediment from municipal pipe maintenance could wind up in the pond.
Large water changes introduce a change when a change is not needed.
Other than diluting some pollutants and adding back some trace minerals, there's no real reason to do a water change.
To deal with pollutants, I try to have as many plants as possible and keep an eye on algae growth.
On the other hand, depending on how a pond is set up, fed and maintained, the plants could benefit from a small water change from the replenished trace minerals.
I'm not saying that the water changes are what caused the deaths, just that it's something extra that needs to be taken into account.

Any chance of vandalism, where someone put something in your pond?

 

[Meyer Jordan]

The symptoms that you described point to either Nitrite or Ammonia poisoning.

 

[bettasngoldfish]

I don't do large water changes unless there is an emergency.
Especially with municipal supply, you never know if there is maintenance being done on the water system and some parameters have been drastically changed. Maybe even some sediment from municipal pipe maintenance could wind up in the pond.
Large water changes introduce a change when a change is not needed.
Other than diluting some pollutants and adding back some trace minerals, there's no real reason to do a water change.
To deal with pollutants, I try to have as many plants as possible and keep an eye on algae growth.
On the other hand, depending on how a pond is set up, fed and maintained, the plants could benefit from a small water change from the replenished trace minerals.
I'm not saying that the water changes are what caused the deaths, just that it's something extra that needs to be taken into account.

Any chance of vandalism, where someone put something in your pond?

I understand Mitch, I suppose old habits die hard though. I can't seem to wrap my brain around not changing water.

I suppose there is always a chance of some neighbor kids doing something but I haven't noticed anything a miss in my back yard. I was wondering if maybe my neighbor (the one close to my pond) had possibly treated her yard with some type of chemicals that got into my pond. When I see her I plan to ask but I don't want to go knock on the door and seem accusatory.

 

[MitchM]

The symptoms that you described point to either Nitrite or Ammonia poisoning.

Ammonia poisoning should show as red inflamed gills.
Does nitrite poisoning have any physical symptoms?

 

[bettasngoldfish]

The symptoms that you described point to either Nitrite or Ammonia poisoning.

Yes, I agree but my tests which I did prior to water change read zero for both ammonia and nitrite.


I was wondering if there was an oxygen issue but I don't see how there could be.

 

[cas]

Sorry about your fish Maria. Could you possibly have too many plants in the pond? With all this warm weather, pond plants can take over a pond. Was there water surface available for oxygen exchange? Do you have an excessive amount of anacharis or hornwort? Just a thought since you have always done water changes, and if there was no way for run-off from the rain to get into the pond.
I don't know much about PH crashes, but maybe the rain changed the PH drastically?

 

[tbendl]

So clarity check, (and again I'm so sorry for your loss). The water test results that you posted, was that before the water change or recent? As in after the fish deaths?

 

[bettasngoldfish]

Sorry about your fish Maria. Could you possibly have too many plants in the pond? With all this warm weather, pond plants can take over a pond. Was there water surface available for oxygen exchange? Do you have an excessive amount of anacharis or hornwort? Just a thought since you have always done water changes, and if there was no way for run-off from the rain to get into the pond.
I don't know much about PH crashes, but maybe the rain changed the PH drastically?

No, I actually have made sure that I have less plants on the surface of the pond this year than I have had in the past. And I do have open water surface. I have both anacharis and hornwort but I wouldn't call it excessive. Yes, Always have done water changes that is why I have a hard time believing that this was caused from a water change. I don't really know much about ph crashes either, I really have been lucky with my water and the type of fish I have kept. I have never had trouble or had to mess around with adjusting it. The thing about the rain that made me suspicious was the fact that this all started the next day following a heavy rain storm. Storm happened on Sunday late evening and into the night, found dead fish Monday night, didn't have a chance to test water until Tuesday evening after work.