Koi upside down

[James WF10]

Hi, quick question.
a friends dad has a Koi pond and they have just rung me for some help.
They have a Large Koi which has just started swimming upside down. The pond is not heated and has been iced over.
i have said that he should break the ice on the surface to allow the pond to gas off, also suggested he get the Koi in a vat of water and get it indoors to at least let the water heat up a bit but he doesnt think he will have anything big enough as it is about 20 inches long. He's got no way of doing a scrape and scope and i've asked for pictures to see if there is anything that would jump out as a sign of what could be wrong with it, so if i get them i will post them also.
Does anyone have any other suggestions please?
Not much else that i can think of offering advise wise.
Thanks in advance.
Cheers,
James

[Manky Sanke]

James,

An initial guess would be low water temperature or lack of aeration causing a build up of gasses such as carbon dioxide or hydrogen sulphide but that would only be a guess. To give better advice we would need more information such as; what is the water temperature, is it completely iced over and does he still have the aeration on?

[James WF10]

i dont think he has air to it and dont know what the temperature is but the whole of the top of the pond was frozen over.
If he breaks the ice will he be likely to see any improvement in the fish do you think?
Makes me relieved i heated and covered mine this year
Thanks for your help.

[Manky Sanke]

Right,

Working with the information available this is a best guess.

Turning off air pumps during the winter is definitely not recommended but koi don't need much oxygen when the water is cold plus cold water holds much more oxygen than warm water so many people can turn off their air pumps and get away with it just using the surface of the water for the gas exchange.

Aeration isn't just about oxygen going into a pond it also removes carbon dioxide and any bad gasses such as hydrogen sulphide which is lethal to fish.

The frozen over surface plus lack of aeration will have allowed the oxygen level to deplete and the carbon dioxide level to rise. That would be a bad enough situation but it could be even worse if there is any rotting silt in the pond. Rotting silt is where bacteria can live and create hydrogen sulphide as a waste product.

The first thing I would do is get the pond aerated. I assume your friend knows that he shouldn't break the ice by hitting it. There are various ways to open up the surface depending on the thickness of the ice and other circumstances such as the layout of the pond. Melting a hole by resting pans of hot water on it is one frequently recommended method (that seemed to take forever when I once tried it donkey's years ago) but any method that doesn't shock the fish by the sound and pressure of hitting it will do.

I would suggest turning the air back on as soon as there is a decent sized hole. That will replenish the oxygen and remove carbon dioxide fairly quickly. If that is the only problem then the koi will recover.

I argue strongly against allowing koi ponds to fall below 4ºC because, during very cold weather, carp in the wild could retreat to the bottoms of lakes where the temperatures were usually no lower than 4ºC and so have not evolved to survive temperatures lower than that.

Koi ponds can easily fall below that temperature and although some fish seem to survive lower temperatures, others don't. This is simply a case of survival of the fittest where those that are tough enough to survive very low temperatures will live and those that aren't so tough won't.

I would like to see the pond temperature raised gently to 4ºC at least but putting a koi into a small unfiltered volume of water and then raising the temperature is not someting I would recommend. A filtered vat, or one where ammonia pollution could be controlled by regular, possibly daily, water changes and with the temperature controlled would be a good idea but not a small tank in the utility room.

There is a possibility that it isn't water temperature or parameter related but the general rule is firstly to get the water quality correct without delay and then look for a parasite or other medical problem if the condition doesn't quickly improve. This would require taking a scrape but we could advise on that, if necessary, after the water is properly aerated.

[James WF10]

Thanks for your help Manky, im trying to get more info but its hard work cos i'm on nights so having to wait a while for responses after asking questions and its going via my friend to their dad and back again.
Turns out the pond wasnt iced over and he has a small waterfall linked to the filtration system which is turned on still. i would have said to turn it off but thought after what you said about getting oxygen in this wouldnt be a good way for it to oxygenate the water, but i also imagine it will be making the water even colder?
I've asked if he is still feeding the fish and told him to tell him not to if he still is as it wont be doing them any favours in this cold weather.
hopefully i'll get some proper info and pictures in the morning from him and i'll post them up when i can tomorrow.

On a seperate note, with my pond, it is covered and heated to about 9 degrees. when i last checked the fish were slightly active but i didnt want to feed them just in case its not recommended. With it being heated a bit, would it be worth feeding them anything at all would you say? or will they be ok until it heats up a bit?
Cheers again for the help.
James

[Gazza]

Hi James,

There could be a few reasons for the problem as Syd has suggested and some fish just get to a point when they are older that they do not like the colder water anymore. I have a Kohaku that does not like the cold weather and recently when my boiler stopped the temperature dropped and the Kohaku was laying on its side but once the water was a bit warmer the fish picked up.

On your pond i would not worry to much about feeding as the fish will last without food for longer than we think,I do not feed my fish through the winter and stop feeding over the Christmas season (normally on New Years Day) and i will not feed them till the weather warms up in the spring.

My reason behind this is if i have fed them good enough through the summer they will have enough to keep them going and over the winter period they will be fine and this will also help them have a time to rest.

[Aqualife2u]

Get the aeration on and check the water parameters, as previously mentioned they should never have allowed the pond to ice over.