Lost 4 fish in the last 24 hours (pond)

[TheresaW]

Can anyone give any advice please? Our pond has been up and running for the last 8 years, lost the odd one here and there, but in the last 24 hours, we have lost 4. 2 were tench, one was a rudd, and one koi.

The filter has been off for a few days as has sprung a leak, and trying to dry out the pit it's in so we can fix it at the weekend. It is a big pond, 6ft deep, approx 2.5m long, and about 1/1.5m wide, so we thought it would be ok for a few days.

1 tench was dead when I got home from work last night, the 2nd and the koi this morning. Our huge ghost carp was in a poor state this morning, and I fully expected him to be dead when I got in from work. I ran the hose into to the pond for a few hours, son turned it off before he left for school, and when I got home, the ghost was pretty much recovered and swimming around happily, but the Rudd had died. Filter is back on right now until we can try and sort it at the weekend. None of the dead fish showed any sign of disease.

We do have a honeysuckle which is growing out of control over the pond, but we make a point of netting the leaves and flowers that are floating out daily.

 

[mattydog]

Not an expert by any means but we have/are having a similar problem with our fish. They started dying with no visible signs of why. Eventually did start with ulcer like lesions so obviously pretty sick. Took one to the vets and turned out they had a whole host of problems which we are just starting to get on top of hopefully. Find yourself a fish vet. Fingers crossed for them.

 

[TheresaW]

Sorry to hear that. Hope you can get it sorted.

We had another dead koi this morning, again nothing visible on him.

On a better note, the big ghost which I really thought we were going to lose yesterday, seems back to his normal self.

 

[shadeofshyness]

Have you tested the water? Without a filter it could be a cycle crash. Good luck

 

[Fanatical]

We had a similar problem a few years back during a period of humid weather. It got gradually worse and eventually one morning we got up and they were all at the top gasping for air. It's something to do with the air pressure and the lack of oxygen in the water. I am no expert but we ran the hosepipe into the pond to create as many bubbles as possible and this seemed to fix the problem. We did have to do it for a good few days though until temperatures returned to normal.

 

[cremedemonthe]

I turned the filter and pump off for a couple of days as I needed to clear some weed that was blocking the intake to the pump.
On day 2 I had one of last year's young ones dead floating on the top.
Whether it has overdosed on tadpoles or frogs I don't know or it was lack of air.I have enough plants and weed to provide air in the pond but also thousands of tadpoles and 12 adult frogs at least as well as all the wildlife that comes with a pond and when I turn the pump off it stops the fountain too which aerates the water, so maybe it was lack of air.

 

[MissTyc]

Sounds like a cycle crash to me. Without the filter running, the bacterial populations are likely to be dying off and that will toxify the water. Even if they are not dying off yet, the water is no longer being pumped through the filter so your nitrites are not being turned into nitrates any more ... A nitrite spike will kill fish fairly quickly .

Did you use a good water primer when you ran the hose into the pond?

sounds like a not nice situation. I guess keep running the hose in to keep the water frehs until you can get that filter back to work. Anticipate that it may not do its job as well as before if the BB have started dying, so best keeping running the hose for at least a few more days after the filter functions.

 

[TheresaW]

Thanks everyone. Thankfully, we haven't lost anymore, although have 2 unaccounted for at the moment. One is a little goldfish, and the other is another Rudd. OH thinks he's seen the Rudd, but I haven't seen it myself.

Filter is running again, and we are putting the hose in morning and night for an hour or so at the moment.

 

[DW Team]

Many years ago in a very hot summer we had the same sort of problem went to the fish centre and they said the water was not oxygenated enough. My water fall pump had given up. He said temp solution was to put the sprinkler over the end of the pond and let the water fall hard into the pond.

Good Luck

 

[TheresaW]

Still not found the Rudd or the missing goldfish, neither have floated to the top, and pond is 6ft deep, can't see the bottom.

All the survivors are now looking healthy and well, got 6 or 7 feeding that have been born in the pond over the last few years. Going by their size, they have to be at least a couple of years old. They all look like Rudd, apart from 1, which is orange with a black tail. Impossible to get pics of them as they dart up for food and are gone again in a blink, but here are some of the big ones I took today.

 

[tabithakat64]

Lovely fish, as others have said it sounds like a cycle crash due to the filter being off.

 

[TheresaW]

We have tested the water, and all is good now, fingers crossed we are on top of it.

The goldfish far right in the top pic was found in this bog at the bottom of the garden when we moved in. We brought him indoors into a tank until the pond was dug and running. Looks like an old man now.

 

[SusieT]

Chlorine? We had this once, someone had added chlorine to the water supplies and as we merrily pumped it in a lot of expensive fish died :/

 

[3OldPonies]

It does sound like a cycle crash, combined with a sudden drop in oxygen caused by the lack of filter and the humid weather. Have the fish been at the top of the water mouthing at all? That is a definite indication that the dissolved oxygen level is way too low and you need to act quickly. Also, the filter media will need to be cleaned before turning back on otherwise you could wash a lot of now harmful dead bacteria into the pond which will lower the oxygen even further. To help increase the oxgyen you could buy a pond size air pump and air stone (or stones depending on how big a pond you have) to help oxygenate the water.

One final thing - you don't have tomato plants anywhere near the pond do you? We lost a several koi one year when we didn't realise that water washing from the leaves after rain had gone into the pond. Evacuation of the pond, filter washes and a pond clean out was the only solution.