Poorly pond fish

[mattydog]

I have around 50 fish in a large outdoor pond. They are mostly goldfish of various types but also a couple of ghost koi and a grass carp. Over the last week they have become very lethargic. Hanging out in the shallows, not moving and not eating and rubbing on the bottom of the pool and flicking. Spoke to the guy in our local aqautic centre who recommended a course of Sterazin P. It's a 5 day course and tomorrow is day 4. Some of them showed an interest in food this morning and they did seem slightly more active, although I think I'm losing one.
Just wondered if anyone had any thoughts as to anything else I can do.
The pond has a filter and pump running 24 hours a day. There is a fountain and a waterfsall so the water is moving. We also have ground water pumped in 24 hours a day so the water is constantly being changed. The pond is established, around 5 years old.

 

[Hairy Old Cob]

Algal Bloom or lots of weed infesting the pond? these may lower the DO levels

 

[blackcob]

Any new additions in the last few weeks?

Can you net a few fish to examine? Rubbing/flicking makes me think of lice.

 

[s4sugar]

How large is large?

Have you had a water sample tested and has the filter been cleared this year? Not cleaned but cleared.

Ammonia can cause flicking.

 

[catxx]

Could water temperature be a factor?

You say you pump ground water - could this have been tainted by anything I.e. pesticides?

 

[mattydog]

Thanks for the replies. Pond is 7 by 8 metres and approx 1 metre deep in the centre. We got some new fish off a friend around 3 weeks ago but they are healthy, he has had them for years.
No chance of pesticides from the ground water...we don't use them.
The filter has been cleared and cleaned.
No weed or algae to speak of. We regularly remove it.
I put salt in last night and upped the dosage of Sterazin P as per my fish man.
They do seem a little better today but still not right. Fish man suspects flukes.

 

[s4sugar]

Thanks for the replies. Pond is 7 by 8 metres and approx 1 metre deep in the centre. We got some new fish off a friend around 3 weeks ago but they are healthy, he has had them for years.
No chance of pesticides from the ground water...we don't use them.
The filter has been cleared and cleaned.
No weed or algae to speak of. We regularly remove it.
I put salt in last night and upped the dosage of Sterazin P as per my fish man.
They do seem a little better today but still not right. Fish man suspects flukes.

Cleaning the filter could have caused an ammonia & nitrite spike. This can cause flicking as can flukes but you can often see signs of flukes.

Have you been using the Sterazin P as directed?
Sterazin P should be used on days 1, 3, 6, 8 and 10 in order to catch the parasites in all stages of their life cycle.

Are you working on the pond being 21,000 litres? A five day course will need 1.5 litres.

 

[mattydog]

Spoke to the people who make the Sterazin and he said to use it daily. He also confirmed we are using the correct dosage and suggested a slightly higher dosage today. They do seem better right now although whether that is due to the salt hit last night, warm weather or higher dose I don't know. Some are not going to make it but the majority seem much better. Fingers crossed....who knew fish could be such a worry. I have enough withe the dogs, cats and horses! many thanks for your suggestions though. I know very little about fish. Google really is my best friend where they are concerned.

 

[s4sugar]

You can use Sterazin daily but course still takes ten days.
What dose are you using?

Has your "fish man" tested the water?

 

[Zero00000]

Our fish were like this a while back, we have a 25x18ft 4ft deep pond with 18ftx5ft 2ft deep for wildlife and spawning, we carried out 50% water change, 30% water change, then 10% for about a week, problem solved, we lost 2 or 3 bottom feedings, golden and green tench and a few rudd, nothing more since, luckily though we have a bottom drain so water changes are easy, our water levels were tested and fine, but the bottom water can have a big contrast to the top