Please Help. Does My Fantail Goldfish Have Fin Fungus?

Hi all,
 
My beautiful fantail goldfish seems to have some white spots on his tail. I noticed them yesterday. Can any of help me to diagnose what it is so that I can do some something urgently to help. I really DO NOT want to lose this fish
 
Here's the details:
 
240 litre tank
Water temp 19 celcius
Stock: 1 fantail goldfish, 2 black moors, 20 x White Cloud Mountain Minnows*
        *12 of the WCMM were added a fortnight ago so may have brought in an infection although none of them are exhibiting any problems so far.
pH - 7.8
Nitrite - 0
Nitrate - 20ppm
Ammonia - 0
GH - 120ppm
KH - 80ppm
 
Please see the photos I have attached (best I could do I'm afraid). Notice the white spot things on the edge of the anal fins? They could have been there for ages as I rarely look at them... not sure if they're related to this problem.
 
 
 


2nd photo

reminds me of ich.
usually its best to only add 6 fish at a time so that the water stats wont change drastically... try to keep the water clean, keep doing your water changed and if more of it shows up, take the fish out and put in ten gallon (make sure its cycled) and treat for ich. its easier to treat fish in smaller tank..

Thank you, as the WCMM are so small I did not think it would be a problem in such a relatively large tank. There are no spots on the body of the fish, only on its tail. The fish is also happy, no change of behaviour yet. That's what led me to think it was some sort of fin fungus.

I don't think this is ich, and unless you're sure it's not a good idea to treat for it.
 
I have a group of 10 longfin black skirt tetras, and usually at some time or another one or two will have some similar spots on their fins, never on the body. Sometimes none of them have it. It seems to come and go, and the best advice I can give is to make sure your water is pristine. 
 
How long has your tank been cycled?

Thanks Old Spouse. I just assumed that the recent addition of the 12 WCMM had brought in some sort of infection. I am not what you would call a keen aquarist so I don't spend every waking moment checking on my tank but I do take the responsibility of ownership seriously. I am ashamed to admit that I do not do water changes anywhere near often enough but I ALWAYS make sure the water quality readings are what they should be.
 
My tank has been cycled for around 3 years I think. I have never had any problems with water quality.
 
About a year ago I think I remember adding aquarium salt when I had a sick fish so I am not sure if any of that salt treatment will still be present in the tank. Maybe that's not even relevant.

When you introduced the WCMMs you probably did add some stress which might account for the breakout. Hard to tell. I have noticed that with my LFBSTs that it doesn't seem to affect them in any way. No tissue is lost and they eat normally, etc. 
 
As far as adding salt, I would only do that in a Q tank and not the main tank, as it seems to stay forever. 
 
Just to be on the safe side, I'd do a decent water change, and then another in a few days, just to be on the safe side.
 
And keep a close eye. This may be something more than what I've talked about. Please keep us posted.

Thank you again for all your help. I will do exactly as you say and do a couple of large water changes this week. I will report back

Hi Spouse,
 
I have done a couple of big water changes since we last spoke 13 days ago. Unfortunately the condition of my fish has got worse. The spots on his tail are now more obvious and there are more of them. Can you (or anyone else) help me to identify what the problem is? Could it be some type of fin fungus or fin rot?
Please see new photos
 
Thank you.

My best bet would be a dose of Melafix, but that's more a tonic than a medication.

Hi Spouse,
 
Sorry for the delay in replying. Following your advice, I rushed off to the pet shop and bought a bottle of Melafix. I have been dosing the tank each evening for the past 3 days. The bottle says I should dose the tank with 31ml of Melafix daily for 7 days and then perform a 25% water change. Goodness knows how the poor fish swim around with that stuff in the tank. It stinks the whole room out! So far I have not noticed any improvement but the condition hasn't worsened. Hopefully it will make a difference soon. I would hate to lose this fish, my two young boys would be devastated.
 
I will keep you informed.
 
Best regards
 
GG

Hi Spouse,
 
Just to let you know that the Melafix has made an improvement now. The fins of the fish definitely look better than they were. Hopefully this will cure it! Thank you so much.
 
GG