Get your water checked out ! Similar thing happened to my ghost koi. Started out as white patches and then turned into filamentous fungus looking stuff. Treated the pond with a formaldehyde based agent and when it cleared up, had the water checked. Showed high nitrite levels causing stress and subsequent infection of the fish. Stopped feeding them for a fortnight and the nitrite levels are now under control. Only feed them every few days. Basically, I was killing them with kindness !

What do you recommend I do then?

Could be saproglenia, best treatment for that is malachite green I believe but it could be a secondary problem caused by poor water quality. I would test the water for ammonia and nitrites and stop feeding them until you know the filter is working properly. Sap can kill the fish so definately get a treatment, malachite green or malachite green and formaldehyde mixed are available in the pond shops.

I have researched it a bit and it looks like my carp has got Saprolegnia (http://www.fishdoc.co.uk/disease/fungus.htm) how would I actaully treat it with this malachite green. Would I have to net the carp out and keep it in a seperate holding tank and treat it in their? Or would I just treat the whole pond?

I treated the whole pond when one of ours got it a few years ago. Be carefull with the malachite green as it is suspected carcinogenic so you dont want to get it on your hands. You can use it as a dip at a higher dosage if you have a holding tank to do this but you'll need to keep it oxygenated and keep a close eye on the fish. Instructions on dosage levels will be on the side of the bottle.

I recommend you buy a water test kit as soon as possible and use it weekly until you get a feel for your fish. Tests should include ammonia, nitrite, nitrate, dissolved oxygen, ph and maybe GH and KH. For fungus malachite will do the trick, use it with formalin and it'll give any parasites you might have a good kick aswell.

Well got some more advice from the guy that built our pond. Got some malachite green and put him in a big tub (on his own) full of pond water and gave him the right dosage of malachite green. I put a bit of oxygenating weed in and put in a bit of an oxygen tablet. This I all did yesterday. Woke up today to find he was dead! What did I do wrong?

Any ideas on how it died, don't want it to happen again?

Did you leave him in the tub overnight? If so then it was more than likely lack of oxygen. Otherwise I'd guess fungus wasn't the only problem going on. As I said earlier you really need to get a test kit and give more details on your setup.

I aint good on disease etc which is why I havent said anything but Malachite green does seem to be the treatment for fungus. However it is a strong medicine and I think easily over dosed. I was on the last treatment for whitespot using King brit, I think, WS3, which contains MG along with some others and I OD'd by 2 drops in something like 26UK gal, I misjudged the squeeze, all the fish, 1" fry, died.
I think I have also seen air should be used. Oxygenators are actually apparently CO2 producers overnight.
It may have been an OD or has been said there was something else.

Stress could also have been a symptom of the fish dying. When they are taken out of their normal surroundings it can be very stressful for them. I would also have said it must have had more than a fungal infection.
Sometimes when they have these things wrong with them a secondary bacterial infection gets in and that is what kills the fish rather than the fungus. I once had a lovely ghost koi which I thought had fungus. I treated with a fungal preparation and five days later did it again. Soon I noticed that his tail was disappearing and so he had also started with finrot. I treated him for that but by that time, he was in a bad way. Eventually he died. I got in touch with a laboratory who told me that he would have died from bacteria which comes as a secondary infection when they are not healthy enough to resist. I don't think you should feel bad or that you have failed in some way because you did everything to save your fish. We just all learn from experience and unfortunately some experiences are sad. I still have pictures of my ghost koi on my website if anyone wants to see them and everything else that is there. It is www.the-horsfalls.co.uk
Alison

How big was the carp? How big was the tub? What's an oxygen tablet and does it react with malachite? A bit of oxygenating weed is no substitute for an air stone and pump.

I was advised by a pond professional to put an oxygenating tablet in and that it would not react with the malachite green. It would have been oxygenated enough with that. The carp was unfortunately my biggest at about 5-6lbs, the tub was just under 3feet wide, and he had plenty of room to move. I was also told by the guy that built our pond that things like the nitrite would be high right now as my pond is new and needs time to settle down. I have not noticed any other problems with any of my other fish. I will try and get a test kit soon.

Thanks,

Sounds like you acted on some "not so good" advice, you should never leave a fish in a tub with any treatment period. and when they are in a tub with any treatment an air stone with a air pump should be used with it, you probebly suffercated the fish most if not all pond treatment reduce the oxygen in the water, some more than others malachite is one of them.

You should not treat a fish unless it is absolutley nessesary, was the white areas on the head rough , smooth or slimey?

Hi Alan, There was something I wanted to ask you about my silver ghost koi. Would it have changed colour to black? The reason I am asking this is because only a couple of weeks after getting it last august/september time it disappeared and I thought it had died or been taken by something. It always slipped under the watercress and didn't seem to want to mix with the other fish. Anyway like I say after about a fortnight or so it just was no more. This week in very bright sunshine I found a black fish in the pond. As it was hiding under the leaves of the marsh marigold I could only see it's tail and top fin which looked like koi. My hubby said he got a quick look at it's face and it did have barbels. I haven't seen it since, but I seem to recall someone saying they wouldn't get a silver ghost as they lose their colouring and turn black. My gold coloured ghosts have kept their colour so I didn't know if this was true or not. Could this fish be my silver ghost koi turned black and if so, it would at least solve the mystery of the disppearing ghost koi.
Alison

Hi Alison, yep it can happen, can happen to almost any koi breed too, you might find it will get some lighter spots or lose the black again and become an "utsuri" I have one that has been a kohacu, sanke, showa and is now a kohacu again lol, although it seems to be losing its orange now too, its a wierd thing, but yep it does happen, it more common for fish to develop black spots or blothches, if its all black its now a "karasugoi"

Alison I bought a 2" koi last year that was predominantly white with a small amount of black (sumi) showing. Over the winter it got blacker and blacker. Its now virtually all black with white lips, we're now calling it jolsen. It disapeared for two weeks a month ago and I thought it was dead, but it was just it's black colour and shy demeanour. It's a very interesting koi but doesn't seem to be growing very fast, now 5", I'll give it another year but if it doesn't start growing fast it'll be on it's way to Kazzies pond if she wants it.
Chris.

Thanks. It has put my mind at rest then. It did seem a shy little thing always hiding in the watercress. I am glad it is still alive. Your Koi's name is very apt Chris. It made me smile.
Alison

Now I think my bream has got the Saprolegnia. Today I have noticed a couple of white enflamed patches on its head. What do you think I should do? I have now bought a small pump which I will put in the quarantine tank to keep him well oxygenated (if he needs to go in it). Should I treat the whole pond with malachite green to make sure nothing else gets it and will I have to turn off the UV light for it to work. My water levels are practically perfect, have been testing them.

What should I do, I don't want to lose another fish to Saprolegnia?

I would treat the whole pond and definately turn off the uv as light deactivates the malachite. Ideally it should be added in the evening but it's best to keep an eye on them for a while to make sure there are no adverse effects from overdosing or anything else that might have gone wrong.

As for the tests, ammonia should be 0 and nitrites should be 0 if the filter is running properly and is adequate.

cautionary note! imho fish hate!!!!!1 quarantine tanks - mine go a wee bit skitzy! and as stress is THE killer give the fish some cover/ shade/ floating plants etc regards jo o/

hello every 1 ive just added Malachite Green ive added 3 doses 10 ml.my ponds about 2500.my fish apear 2 have white spot and fin rot my water conditions are ok my filter and pump are ok ive got a 4500 filter.mainly got koi all about12-15 inch long have i done the right thing adding the Malachite Green.the fish did actualy start becoming dozy and slow about the same time a little moss weed apeared around my pool at the moment the Malachite Green- seems to be killing the weed off.ill send a post in the next couple of days saying how ive got on if any one can help as this is my first pool i would be very greatfull cheers

Hi we have mixed fish in our pond, common carp, mirror carp, golden tench.chubunkin, commet, koi carp, ghost carp, sturgeon and they have been together for nearly 2 yrs. They are all healthy and fine except for 1 of the mirror carp. It had on its head 9 mnth ago 2 white round spots and all of a sudden over the last 4 weeks they are on its body as well it it eating ok and acting no different. None of the other fish have this problem, What could it be? please help thanks karen.

nearly 2 months ago all my fish looked like they only had a week left 2 live they would nt feed all there colours had faded they became marginal and i could literaly lift them out the water,after looking into fish desease potions i came across malcanite green i gave my pond the required dosage the water turned ink green,within 24 hours the malcanite had settled nearly leavin still a faint green colour in the water,the fish where more alert and feeding again,within a week my pool was back 2 full life all fish are still well,ive recently added malcanite green again it keeps the pool in perfect condition my fish are all still well.dave

One word of caution, dont forget that male fish (all male fish) get white bits on there head from April to August, and it may vary in size and spread on the head and gill plates, these are breeding turbicles, and people have often mistaken them for something wrong!

Hi all , It's been a while but Pearl and I are back into ponding with a small(5500ltr)ornamental pond.
So sorry to hear of the worries over fish health. On a similar note we need to get a water quality test kit (Am, Nitrite and Nitrate). I note that there is an even bigger range of kits on the market today- including liquids, paper and tablets. Any recommendations on which we should get ?

Hope someone can help! Our 5yr old carp, Colin has had a white spot on his head (actually between his head & his mouth) for the last coupe of weeks. Doesn't seem to cause him any problems, but it is slightly larger & today he didn't feed (MOST UNLIKE HIM!) & seems lethargic. We had a problem with our pond in spring - the UV wasn't working properly & we lost a few shubunkins (ulcers & one had what looked like a rotting mouth - the flesh was being eaten away - poor thing) Water now seems fine (although haven't got a test - must do that tomorrow. All the other smaller fish seem healthy - but please help, cos Colin is so special, he's lovely! We did replace the water some time ago & used malachite green, which seemed to help conditions, but perhaps we need to use it again or is it something else? I'm a bit confused as to how to treat whatever it is. Help!! Thanks

If you can I think you should put Colin in a quarantine pond or tank until you have treated him.
I'm afraid I don't know much about fish, but I'm sure someone will help. It sounds like a fungus though

I Bought 3 ghost carp and put them in with my gold fish

they are about 6 inches and i noticed one has a white patch below its eye i also have a brood of baby goldfish which are growing nicely and am concerned that they mignt be contaminated .
Is it better to remove the sick fish or can i treat it in the pond.
I need some help please