Major fish die off Help!!

[SEEKER99]

I have had ponds now for over 25 years. I have never had any issues , I may lose 1 or 2 fish a year, maybe.
I am on well water my own, have great water, I have been told I have the perfect Eco system, and many of
the people who raise and breed koi often send their new clients over to see my pond,. I have plants which I maintain every spring taking out the dead as well as roots, I have mesquito eaters in there as well. i have turtles an koi and gold fish.
It is 16000 gallons when full.

About a 3 months ago i had as ,amy as 50 fish die mostly large die , in 1 or 2 nights , everyone else seemed fine.
I added some clear pond, Did not have any problem, bnut fish were acting strange.Like they were afraid.
Then today they started dying as well I lost an additional 50 or more . I cannot find a reason for it.
I am devestated, I have now started a clean oiut and salt treatment but unsure still of the cause.

I am unsure as to how much salt to add and how to add it.

 

[ZEROPILOT]

I'm assuming that you test the P.H. etc.
About once every year, year and a half, I have had this same strange thing happen.
I have my pond situated to receive run off rain water from my roof. And here it rains a LOT.
At first I thought acid rain? I tested and it was still about 7.9.
But I still had massive die offs. And the surviving fishes hovering at the bottom and acting strange.
No ammonia spike. No temperature drop or increase, etc.....Though these die offs do happen when the weather is hot. From June to September. I'm thinking its something that blooms or is in the air that the heavy rains bring in in greater quantity from the roof run off. My new pond will do without this feature.
I'll follow this thread and hopefully someone will chime in with a suggestion.
I wouldn't ad salt unless there is a known issue. I did massive water changes. But I have much smaller ponds than you.
I'm a novice and I don't want to insult you by offering advice that you probably already know.
I'm assuming that you have a large, comprehensive water testing kit?

 

[Jhn]

What are your water parameters? Test with test kit and put numbers to it....ammona, nitrite, nitrate, ph.

How many fish are in your pond?

You said you have large fish, how large? 12", 2-3'?

What type of filter system does it have?

How many turtles and size?

Answering these questions will enable everyone here to help you better.

You have a large pond, but also sounds like you may have a large fish load in the pond. Add in turtles, which are extremely messy eaters and it could be overwhelming your filter system. Can't say for sure until above questions get answered.

I would wait until you can determine what is wrong with the fish before starting a treatment regimen especially in the whole pond.

Sorry to hear that you are losing fish that can be very frustrating.

 

[Nyboy]

Sorry

 

[Meyer Jordan]

Is only one size fish affected or all sizes?

 

[sissy]

could be lack of oxygen and heat makes it worse

 

[Gemma]

Sorry for your loss!

 

[qclabrat]

condolences on your loss
sounds like you need to first do a regimented testing of your water
follow @Meyer Jordan directions and he & others here will help you diagnosis your problem

odd that you had the same occurrence a few months ago
let us know more details on what you have done or observed
check back often and we'll help you get through this

 

[sissy]

heavy rains can wash all kinds of bad things into a pond also

 

[Faebinder]

..................................................... everyone else seemed fine.
I added some clear pond, Did not have any problem, bnut fish were acting strange.Like they were afraid.

What did you add? Clear Pond.. is that an anti-algae liquid? Cause algae in a pond absorbs fish excrements and urine... you could have had an ammonia spike post adding this that killed the fish.

 

[ZEROPILOT]

could be lack of oxygen and heat makes it worse

This could very well be what happened in my case.

 

[Meyer Jordan]

If both large and small fish were affected then it is not likely an Oxygen problem.
What are you using for source water...municipal or well?

 

[SEEKER99]

What are your water parameters? Test with test kit and put numbers to it....ammona, nitrite, nitrate, ph.

How many fish are in your pond?

You said you have large fish, how large? 12", 2-3'?

What type of filter system does it have?

How many turtles and size?

Answering these questions will enable everyone here to help you better.

You have a large pond, but also sounds like you may have a large fish load in the pond. Add in turtles, which are extremely messy eaters and it could be overwhelming your filter system. Can't say for sure until above questions get answered.

I would wait until you can determine what is wrong with the fish before starting a treatment regimen especially in the whole pond.

Sorry to hear that you are losing fish that can be very frustrating.

I had about 20 16" or larger, I had 30 6" give or take 2 to4 "s, and unknown count of small. There are 11 turtles only 3 are bigger that 5 or 6" the rest are very 4 " and 3".
My filtration is 2 large cast iron enamelled bath tubs with pea gravel,and lava rock and filter which fill from the bottom up, . We have one pump just circulating and the othe r pumping to the filters which them comes back in in a waterfall, and over rocks and on side of pond.
I am not on city water, have my own well.

As I said before though I have been doing ponds for 23 yrs and have never experienced this.

 

[Meyer Jordan]

When is the last time that you had the well water tested.....for Heavy Metals?
The chemical and mineral profile of well water can rapidly change depending on geographical location.

 

[sissy]

I got my well tested in the spring after all the heavy rain .But my well is 400 feet in the ground and I know of several shallow wells out on Martin Drive with jet pumps that had to be condemned because of run off from cow pastures near the houses .