Fish seem lethargic

[Ian 1980]

We moved into a property in November which has a pond in the garden we’re there was one fish, the pond has been established for 15 years
We’ve since bought 4 goldfish and 2 shabumbkins everything was fine with water I was cleaning pond filter once a week
Then we had a visit from a heron which eat a couple of are fish and resulted in spoiling the fish and they hid under the waterfall
Since then we’ve put a not across the pond but not directly in the pond and we’ve had frogs spawning so plenty of tadpoles, since then the fish have seemed very lethargic so I thought it may be the tadpoles taking up the oxygen so I bought a air filter with a stone a couple of days ago but doesn’t seem to be improving

Can anyone help

 

[Hound Heaven]

We moved into a property in November which has a pond in the garden we’re there was one fish, the pond has been established for 15 years
We’ve since bought 4 goldfish and 2 shabumbkins everything was fine with water I was cleaning pond filter once a week
Then we had a visit from a heron which eat a couple of are fish and resulted in spoiling the fish and they hid under the waterfall
Since then we’ve put a not across the pond but not directly in the pond and we’ve had frogs spawning so plenty of tadpoles, since then the fish have seemed very lethargic so I thought it may be the tadpoles taking up the oxygen so I bought a air filter with a stone a couple of days ago but doesn’t seem to be improving

Can anyone help

If I had to guess, and of course that's what I'm doing, I'd say the fishes might be spooky after seeing that heron. I keep a milk crate in my pond and my goldfish hide in it a lot of the time. Maybe you should provide a hiding place for your fish? I can't speak to the water conditions, good luck.

 

[j.w]

@Ian 1980

 

[GBBUDD]

Water could still be cool and the fish get this way due to cold water.