Spreading White

Hi, i started a new topic yesterday called fin rot or something else and mentioned that this 'white' patch had begun yesterday morning by a tiny white spot andad advanced by tea time... I have attached same photo of him plus photos this morning... Hopefully I might get some different thoughts... It's started on his body now... I treated with melafix last night. 64L tank 0.25 ammonia 0 nitrites and 20 nitrates - 8.2 ph as water very hard.
1st photo yesterday 2nd this morning

The 0.25 ammonia is the problem. Aquariums should have no ammonia or nitrite. How old is this tank? Was it cycled? Have you recently changes the sandbed, filter media or anything that could have caused a mini cycle ?

As a newcomer, I was never told about the nitrogen cycle when i got my fish, it wasnt until a couple died that i decided to look into things and ask why?  Naturally from the start of finding out that information I have been doing everything in my power to protect my fish, and for 4 weeks solid helped them through by doing daily water changes.  The ammonia and nitrite eventually went to 0 and Nitrates went down to 20.  I tested and continue to test twice daily with liquid tests and when everything stayed still I introduced four new fish.  The other three are fine but this one has come down with this problem.  Hes still eating, but only has one fin to use on his side as the other has been held shut by this white stuff.  I have only had them 48 hours.  I have changed nothing...all media is the same.  The only drastic thing I have done is a week ago is i rinse the filter media in tank water and cleaned the glass and hoovered the gravel and sand a little, also rinsed the couple of fake plants I had in tank in tank water.  I do have live plants too.  I can understand the ammonia going up to 0.25 as with the new fish was expecting changes and have done a few water changes to get it back down to 0.  The readings I gave you are recent ones before water change.

.25 ppm of ammonia on an API test kit in 8.2 pH water at the temp. Fj reported in chat last night means the level of the toxic NH3 form of ammonia in the tank is .0202 ppm. This is not causing any damage in the short run. That fish is not suffering from ammonia burns, it is something else.
 
The pictures are poor but it looks like the fish has white about the lips as well as other areas. If so I would suspect columnaris as the problem.
 
Fj did you compare your fish's symptoms to the the disease site I sent you to last night? If you did not find anything you felt matched exactly, go back and read up on the columnaris description.

 
Mouth Fungus
   Symptoms: White cottony patches around the mouth.
 
   Mouth Fungus is so called because it looks like a fungus attack of the mouth. It is actually caused from the bacterium Chondrococcus columnaris. It shows up first as a gray or white line around the lips and later as short tufts sprouting from the mouth like fungus. The toxins produced and the inability to eat will be fatal unless treated at an early stage. This bacteria is often accompanied by a second infection of an Aeromonas bacteria.

     Penicillin at 10,000 units per liter is a very effective treatment. Treat with a second dose in two days. Or use chloromycetin, 10 to 20 mg per liter, with a second dose in two days. Other antibiotics can also be effective. Kanacyn (kanamycin) will treat both bacteria at once. Maracyn (erythromycin) is effective against C. columnaris, and using Maracyn 2 (minocycline) in conjuntion with it will treat the Aeromonas bacteria as well.

Click to expand...

from http/animal-world.com/encyclo/fresh/information/Diseases.htm#MouthFungus
 
Note this disease is also referred to as Flexibacter columnaris.

Yes I did look at the link you sent and did mention my thoughts about it last night but think you were busy.....I did wonder about Columnaris, but some pictures looked like cotton wool, this doesnt, it looks like I have brushed him with paint...its very smooth...  His fin is clamped one side and its a bit more white than yesterday plus it looks like its begun on his side too...he cannot of course use the fin.
The line of 'white' has just carried on from his fin towards his body in such a perfect line, just again like hes been dipped in something.
He is eating ok but looks sorry for himself.  I cannot be so definate about the mouth area...looking at the picture I too thought it looked light but when looking at him directly it isnt there.
I am off to the pet store in a short while and am a little undecided whether to get fin rot/fungal treatment or go straight for the antibiotics if they have some.
If it is this columnaris I think its contagious isnt it?..with no emergency tank then I have to act fast I guess.
Any other suggestions would be greatly appreciated.

Okgot home from work and he's died, so whatever it was has spread in 48 hours...also when I got home another fish had developed the same thing but on his head, and in the space of 24 hours has killed him. I am at a loss and don't know what to do. Now I have an ammonia spike going on and am wondering what on earth is going on? Could there be anything causing this from a new ornament? I did wash it extremely thoroughly in tank water.
Think it was columnaris 'cotton wool disease' 'saddle back' as the signs seem to be there....
Can anyone tell me whether I need to treat the tank still even though I cannot see any other fish with it?