[shirley ingham]

I know this may seem a stupid question but............. We lost an 8" x 3 yr old koi this week. Not a mark on it. We tested the water all seems OK . The ph was at 6.5 but it is a re-done pond & there is a bit of algae bloom in it. (we are working on that & know that filtration is a little inadequate at the moment, but nitrate,nitrite & ammonia levels are fine). Next - oxygen levels should be OK as we are running a temporary system which kept them going while pond was being re-built in the hot weather so that should still be adequate
In the last couple of days several of the koi (not always the same ones & not always at the same time) are just 'Hangin' about man........' just under the surface & seem a bit lethargic..........
Question - Is it just the temperature?????????????????THOUGHTS PLEASE

 

[Snakes r grreat]

How deep is the pond? And are they gasping at the top, or just staying there? An algae bloom is not a problem for the fish, they will actually prefer it, its just doesn't look very nice. Are you also feeding them still and what is the temperature in your pond?

 

[Andyman]

The reason there lethargic is as you say the temperatre, so thats nothing to worry about, tho i stop the rapid water movement at the top, your better off maybe just buying a pond heater or something to stop the water iceing over if the weather gets to cold, otherwise you can switch everything off, aswell if there still feeding i'd reccomend wheatgerm, as its alot easier for the fish to digest in the cold weather !

 

[shirley ingham]

update

Thanks for that. There is an update . One more fish didn't look too good so we took it to aquatic centre nearby & they did a scale scraping only to find we have flukes. They also checked the water & concurred with us except that they got the ph at 5 not 6.5 that we had. So with recommendation we ph buffered. Then we have treated for flukes & keep our fingers crossed.
The fish are not really gasping but just have their head right at the surface
The pond is generally 4ft deep or a couple of inches more in places
2,000galls. I had been feeding them but they have gone off & I do normally feed wheatgerm in late autumn & spring. I don't have a heater as I thought they were very expensive to run.
I think I might loose this latest one but am trying not to. He is a 14" + Israeli koi which was my mothers & he is about 20 yrs old.