what could of killed our fish??

[wags]

we have had our pond for a little over 2 years old..we had a lot of trouble trying to get it clear but this spring it was finally clear..I think it just took awhile for the pond to get good algae in it or something..So this year we haven't added any chemicals to it or anything..Everything was doing wonderful..The fish were growing and eating well then this morning when we woke up they were all dead..6 goldfish and 3 koi..I couldn't believe it..It had stormed last night so I was wondering if they were struck by lighting or what?? The pond is right next to the house and we never heard any real loud lighting strikes.. If it was lighting you thought you would have heard it hit.. The pump is still running and the pond is still as clear as it was before.. We are very sad and puzzled..Does anyone have any Ideas of what could of happened?? Thanks wags    I live near danville Ill.

[miguynmkoi]

Soooo sad!  Is there water runoff from something that had chemicals applied on it?  Don't know anything about storm/lightning.

[karen J]

It could also be caused by a pH crash from all that rain. Do have the kit to test your water?

[tootsie]

A few days ago I found one of the pretty Koi floating in the pond, dead I managed to get it out with my long  net. Right away I knew it was the work of the darn heron! Two big pokes on either side of the fish! I have seen heron  here two at a time just working the pond. Maybe if I get more lily pads, they will have lots more cover

[KatFish]

Sorry.  Been a bad few days for fish here  :'(  Did you get mosquito spray too?  I have never had problems when my neighborhood gets sprayed, but maybe your areas get something different?  Maybe you and Sushi got the same bad batch.   

[Julles]

Wags, I am so sorry to hear that.  What a shock!

I, too, feel it must have to do with something that washed into the water, or perhaps a pH spike, as suggested. 

[wags]

we tested the water its fine..we have neighbors that have ponds and theres are fine..just don't understand.......... :'(

[frogman3]

Wags, what did your PH test at? Every pond is different and you can't compare your neighbors, if you had a lot of rain, under certain circumstances it can cause a PH crash which can spell quick death for your fish.

[LeeAnne151]

Low oxygen can do it too. Usually the biggest fish die first. This is very common with small ponds and summer heat. I don't know what size your pond is or what aeration you have.

Predators don't leave all the bodies. It has to be something chemical or physical like an electric shock/poison/low oxygen.

[wags]

Our ph balance was perfect by our testing and the pet shop testing..this is really a mystery to us..also we have plenty of aeration..also no chemical run off..we also bought 5 feeder goldfish and so far their still alive so far..Just don't know

[Kittyzee]

I'm so sorry for your loss.  Sometimes it seems we do everything right, and we still lose fish.  I hope you find an answer.   :'(