Over the last weekend I have lost 7 koi and am at a loss as to why. A few
days ago the koi in my pond generally stopped eating, having previously been
ravenous feeders. I tested the water and all tests proved "normal" (ph 8.0,
nitrites 0.1, chlorine 0, ammonia 0) except for oxygen which had dropped to
less than 1ppm. I run with 2 filters dropping approximately 1500 gallons
per hour, two spitters and a fountain running at 250 gallons per hour and
can not understand the low reading. I immediately added an air pump with 4
air stones and continue to run that as well, although the oxygen reading has
only gone up to 2ppm today.

The fish that have died have all isolated themselves from the others, and
been very slow moving, although do evade my attempts to net them, right
until they are nearly dead. I have noticed that all the dead fish had a
heavy mucus coating on their skin making them extremely slimy, and that some
of their scales had become very prominent (I have posted some pictures of my
latest loss on http://deadfish.mysite.freeserve.com/).

My pond is approximately 2250 gallons with koi, goldfish and orfe. This
only seems to be affecting the koi though. I am in the UK and temperatures
have been very high recently, with the water temp in the pond reaching about
24 C.

Any help as to how to help my remaining fish, as well as how to improve the
oxygen level in the pond would be greatly appreciated.

TIA

"John" wrote in
message
...
Over the last weekend I have lost 7 koi and
am at a loss as to why. A few
days ago the koi in my pond generally
stopped eating, having previously been
ravenous feeders. I tested the water and
all tests proved "normal" (ph 8.0,
nitrites 0.1, chlorine 0, ammonia 0) except
for oxygen which had dropped to
less than 1ppm. I run with 2 filters
dropping approximately 1500 gallons
per hour, two spitters and a fountain
running at 250 gallons per hour and
can not understand the low reading. I
immediately added an air pump with 4
air stones and continue to run that as
well, although the oxygen reading has
only gone up to 2ppm today.

The fish that have died have all isolated
themselves from the others, and
been very slow moving, although do evade my
attempts to net them, right
until they are nearly dead. I have noticed
that all the dead fish had a
heavy mucus coating on their skin making
them extremely slimy, and that some
of their scales had become very prominent
(I have posted some pictures of my
latest loss on
http://deadfish.mysite.freeserve.com/).

My pond is approximately 2250 gallons with
koi, goldfish and orfe. This
only seems to be affecting the koi though.
I am in the UK and temperatures
have been very high recently, with the
water temp in the pond reaching about
24 C.

Any help as to how to help my remaining
fish, as well as how to improve the
oxygen level in the pond would be greatly
appreciated.

TIA

John,

Have you tried koivet.com?
They have a lot of info which might be
helpful to you.

I am sorry for your loss.

Best wishes,

Jeannette

Dear John

Your problem is being caused by a number of factors which a-

1. your pond water temperature is too high. You should flood your pond every day in warm/hot weather to ensure it remains cool.

2. oxygen, oxygen, oxygen. You must make sure your pond has plenty of oxygen. It isn't enough just to fill it with plants you must have constant running water to force oxygen into your pond water. The best way to do it is to use a hose pipe positioning the hose high up so when the water hits your pond water it creates millions of tiny bubbles that are actually forced into the water.

3. with reference to the 'slime problem' - when fish have been dead a couple of hours they develop a 'natural' mucus which covers their body. Other factors which cause fish to become slimy are, fin rot, cotton wool fungus and costia. Also, did you know that frogs actually grab fish and spawn all over them? Their slime clogs the fish's gills and they suffocate. If l were you l would buy a good quality anti-fungal treatment making sure you mix the exact amount and treat your pond with the solution for the prescribed time. At the same time follow 1 and 2 above and your fish should remain fit and healthy.

Good luck

sandie

Incidentally John,
l tried to look at the pics you posted but unfortunately the page won't load. Is there any other way l can see them?

Regards
sandie