Fish dying

[Kimberleyc]

Hi everyone, I'm really new to this. Moved house last and acquired a "leaky" pond which has been completely revamped with new liner etc and is around 7-8000 gallons. It's been well planted with marginals, lillies etc for around 18 months and have a pond expert 12000 and a 6000 pump...all was well until I started to add fish
I began 2 months ago by adding 5 shabunkins and then a month later,, 2 baby koi
The weather has been u bearable hot but all was fine until a couple of days ago when a shabunkin died. Over the past 2 days, I have lost another 3. Koi seem fine
Water is tested regularly using Nt lab drops
PH 7.5
NO ammonia or nitrates present, no visible algae and oxygenation plants thriving
Obviously upset to lose fish, has anyone any ideas
Many thanks

 

[Jhn]

Where they acting any different before they died? Any pics of your pond? Type of filter system in the pond? How is water returned to the pond? Have you added anything to the pond like chemicals?

 

[Kimberleyc]

Many thanks Jhn I have enclosed pics of pond, as you can see it's not yet finished as we plan to incorporate the filter system into a waterfall
Filter system is a pond expert, water is clear. Fish went downhill rapidly over a period of a few days and started to lay on the bottom of the pond
Have added a pic of the most recent victim

 

[Kimberleyc]

Filter system is pond expert spinclean 20,000, not 12,000 as previously stated

 

[Criscar]

Many thanks Jhn I have enclosed pics of pond, as you can see it's not yet finished as we plan to incorporate the filter system into a waterfall
Filter system is a pond expert, water is clear. Fish went downhill rapidly over a period of a few days and started to lay on the bottom of the pond
Have added a pic of the most recent victim

Might be worth treating the pond with Prazipro or something similar for parasites since the fish are gradually dying like they are spreading a disease amongst themselves. Have any ducks or other aquatic birds been seen at your pond lately? They can carry diseases with them.

In the fish photo, that fish, the eyes look very cloudy, which can be caused by parasites or bacterial diseases (the Prazi would not treat bacteria, though, just FYI, only parasites). Were there sores or other signs of illness or injury?

 

[Jhn]

@Kimberleyc some how missed your response on Saturday.

While disease can certainly be brought in on ducks and birds it is usually due to poor water quality or someth8ng a miss with the pond.

Couple things I see that could be an issue to why the fish aren’t doing well. You said it has been extremely hot, looks like your pond is in full sun, that little white pipe is the only water flow/circulation in the pond, correct? Issue could be with poor circulation and low oxygen levels in the pond.

Your filter even by its rating is undersized for your 8000 gallon pond. If it were me I would increase circulation in the pond to 1.5-2x pond volume, even add an aerator to help with oxygenation.

Add waaaay more plants, you don’t have that many. Would first go with water hyacinth and water lettuce, as they will help shade the pond and spread quickly. Try marginals like water cress, water celery, creeping Jenny, water forgetmenot, parrots feather, all can just be shoved between rocks in the pond and will spread quickly. Ideally you want around 60% coverage on the water surface, especially on a pond in full sun.

Also check your ph in the morning and evening to see if it is swinging. A ph that isnt stable is very stessful to fish, if it is having a big movement in 24 hrs, test your kh it is most likely low. By the by, 7.5 ph is fine just want to make sure it is stable.

 

[Kimberleyc]

Might be worth treating the pond with Prazipro or something similar for parasites since the fish are gradually dying like they are spreading a disease amongst themselves. Have any ducks or other aquatic birds been seen at your pond lately? They can carry diseases with them.

In the fish photo, that fish, the eyes look very cloudy, which can be caused by parasites or bacterial diseases (the Prazi would not treat bacteria, though, just FYI, only parasites). Were there sores or other signs of illness or injury?

@Kimberleyc some how missed your response on Saturday.

While disease can certainly be brought in on ducks and birds it is usually due to poor water quality or someth8ng a miss with the pond.

Couple things I see that could be an issue to why the fish aren’t doing well. You said it has been extremely hot, looks like your pond is in full sun, that little white pipe is the only water flow/circulation in the pond, correct? Issue could be with poor circulation and low oxygen levels in the pond.

Your filter even by its rating is undersized for your 8000 gallon pond. If it were me I would increase circulation in the pond to 1.5-2x pond volume, even add an aerator to help with oxygenation.

Add waaaay more plants, you don’t have that many. Would first go with water hyacinth and water lettuce, as they will help shade the pond and spread quickly. Try marginals like water cress, water celery, creeping Jenny, water forgetmenot, parrots feather, all can just be shoved between rocks in the pond and will spread quickly. Ideally you want around 60% coverage on the water surface, especially on a pond in full sun.

Also check your ph in the morning and evening to see if it is swinging. A ph that isnt stable is very stessful to fish, if it is having a big movement in 24 hrs, test your kh it is most likely low. By the by, 7.5 ph is fine just want to make sure it is stable.

Many thanks to @Jhn and @ criscar, we have now resolved the issue. We were very lucky to have found a local , very small pond supply shop and the owner came a d had a look ( at no charge)
He suggested that the filter wasnt big enough and that we also didn't have enough oxygen, he was amazed at the clarity of the pond but suggested that as we only have a few fish, we have only now encountered problems due to the hot weather as it was 30 degrees for a few days
We have raised the return pipe to give more splash as water is returned to pond (pending the building of a waterfall) and added 2 large air stones and a pump. Fish recovered quickly and I am thankful that I only actually lost 3. We have also treated with a bacterial treatment

 

[Kimberleyc]

Might be worth treating the pond with Prazipro or something similar for parasites since the fish are gradually dying like they are spreading a disease amongst themselves. Have any ducks or other aquatic birds been seen at your pond lately? They can carry diseases with them.

In the fish photo, that fish, the eyes look very cloudy, which can be caused by parasites or bacterial diseases (the Prazi would not treat bacteria, though, just FYI, only parasites). Were there sores or other signs of illness or injury?

@Kimberleyc some how missed your response on Saturday.

While disease can certainly be brought in on ducks and birds it is usually due to poor water quality or someth8ng a miss with the pond.

Couple things I see that could be an issue to why the fish aren’t doing well. You said it has been extremely hot, looks like your pond is in full sun, that little white pipe is the only water flow/circulation in the pond, correct? Issue could be with poor circulation and low oxygen levels in the pond.

Your filter even by its rating is undersized for your 8000 gallon pond. If it were me I would increase circulation in the pond to 1.5-2x pond volume, even add an aerator to help with oxygenation.

Add waaaay more plants, you don’t have that many. Would first go with water hyacinth and water lettuce, as they will help shade the pond and spread quickly. Try marginals like water cress, water celery, creeping Jenny, water forgetmenot, parrots feather, all can just be shoved between rocks in the pond and will spread quickly. Ideally you want around 60% coverage on the water surface, especially on a pond in full sun.

Also check your ph in the morning and evening to see if it is swinging. A ph that isnt stable is very stessful to fish, if it is having a big movement in 24 hrs, test your kh it is most likely low. By the by, 7.5 ph is fine just want to make sure it is stable.

Many thanks to @Jhn and @ criscar, we have now resolved the issue. We were very lucky to have found a local , very small pond supply shop and the owner came a d had a look ( at no charge)
He suggested that the filter wasnt big enough and that we also didn't have enough oxygen, he was amazed at the clarity of the pond but suggested that as we only have a few fish, we have only now encountered problems due to the hot weather as it was 30 degrees for a few days
We have raised the return pipe to give more splash as water is returned to pond (pending the building of a waterfall) and added 2 large air stones and a pump. Fish recovered quickly and I am thankful that I only actually lost 3. We have also treated with a bacterial treatment

 

[WaterGardener]

Keep an eye on your water parameters. Putting bacterial treatment in your pond can kill your beneficial bacteria and your pond will have to start the nitrogen cycle again.
That will result in a spike in ammonia and nitrite, both problematic for the fish.

 

[Kimberleyc]

Many thanks @WaterGardener , am checking regularly and so far no ammonia or nitrate.
Would you advise adding beneficial bacteria once this treatment is completed?

 

[WaterGardener]

Unless you buy the live bacteria that has to be shipped overnight, and that is very expensive, there is no need to buy bottled bacteria from the pet store. That is not the type you need and what you do need will not live long enough to be bottled, shipped by regular means, and sit on a shelf for an unknown amount of time.

I would keep some Prime or Safe (the powdered version of Prime) on hand in case you need to bind the ammonia and nitrite if you see it starting to rise.

 

[Mmathis]

Is your pond 8000 gallons, or 8000 liters?

 

[Kimberleyc]

Hi @ TurtleMommy, my pond is around 8000 litres, apologise as I have put gallons

 

[Mmathis]

And how deep is it? I ask because you mentioned the heat there. Just to be on the safe side, you might want to check the temperature of the water. A shallow body of water isn’t going to stay as consistent and cool as a deeper, larger one will.

 

[Kimberleyc]

Its approx 3ft deep over half of the pond. We have now put air stones at the shallower end
Thankfully the hot weather has broken and it's much cooler with rain. Fish appear to be doing ok and no further loss