Pond fish deaths

Bijdezee

I wasn't sure where to post this but some pond questions are here so.. 

We had the water tested after we lost 4 of our five comets. It came back fine, perfectly balanced they said. I found that strange after the fish died. We have refilled it with rain water, reset the plants and later on put the remaining fish back in. A couple of hours later she was spawning again  :'s, no males there but she seems much perkier. I got the baby fish in a bowl and some special food from the pond shop. Enormous tub to feed 8 microscopic fish.

Leaves us still not knowing why those fish died. Anyone with experience of this? 

Pete.8

I've kept pond fish for many years and the only times I can recall mysterious deaths is following a spell of warm weather then stormy weather.
I can't think why though and it may just be coincidence

If the water was very green and a warm day, it may have been lack of oxygen

Bijdezee

That's interesting because we did have some thunderstorms and really torrential rain before it happened. 

We have a small fountain  and oxygenating plants but no filter. I do change about 20 per cent of the water twice a week as recommended, with rain water. 

Would it help to cover it if there are more storms do you think? 

Pete.8

Hmmm
I doubt the thunder and lightning scare the fish, but I don't know.
Maybe it has something to do with the ozone produced by the lightning or the drop in pressure as a storm approaches... a bit of a mystery
I use tap water for the fish pond and change about 10% if the weather is close and stormy, and like you I do it twice a week. Otherwise I only top the pond up when needed. I keep feeding on the light side in very warm weather too.
I only have 2 very big koi in the pond now - the herons ate the rest many years ago

Sheleen

We had four unexplained deaths of the finned variety this year - straight after a long, extremely hot spell. Two adult fish (one ghost koi, one fantail goldie) and two smaller koi of about three months old. Nothing to show that there had been anything wrong with them - no predatory marks or any signs of disease. I just assumed it was due to the heat. The older koi was about 14 years old.
Funnily enough, we do have one koi in our pond who has a weird shaped body - like he's been bent in half and it kinked him. A koi specialist told me he was probably too close to the surface when lightning struck, and this is the result. Fish, in general, aren't frightened by lightning or thunder storms - mine even put up with the dog (once) and cats (four times between the three of them) falling into our pond. 

hogweed

If there is no sign of disease and the weather has been very warm I would put it down to lack of oxygen. Your small fountain may not have been enough...…….

Bijdezee

@hogweed., you might be right there. Warm weather makes it lose oxygen faster I suppose. 

Bijdezee

hogweed said:

If there is no sign of disease and the weather has been very warm I would put it down to lack of oxygen. Your small fountain may not have been enough...…….

Although... The pond its self is very small so it ought to be enough as the movement of water reaches over about half of the surface. 

Hostafan1

I lost over 30 fish overnight to an otter.

Brexiteer

Hostafan1 said:

I lost over 30 fish overnight to an otter.

I bet you were devastated I know I would have been 

Hostafan1

No, I wasn't, not really . The fish were there when we moved in .
The pond is now full of toads and frogs and newts and damsel flies.