Peppered Cory Blister Like Spot?

[captaincrash84]

Hi I have 4 Peppered Corys and my biggest one has this strange white blister like spot. It doesn't look like white spot as it looks more growth like but it doesn't seem to be bothering him and the others don't have anything on them.

Its not the best of pictures but he doesn't stay still very long!

Its quite white/pus like in colour and looks like it sticks out a bit like a Zit on your face does.

Any idea what it is?

 

[captaincrash84]

Here is a few more pics

 

[captaincrash84]

Well i put my Blue LED lights on and after closer inspection it looks quite fuzzy in texture and could it be this:

http/www.aquatic-hobbyist.com/profiles/d...columnaris.html

Just did my readings:

Ammonia = 0
Nitrite = 0
Nitrate =0
P.H.7.4

There is no bulling in my tank and its only the 4 Peppered Cory in the 125 Litre tank (I did have a few fish with white spot but that is all over and 125 L tank was treated and the other fish are now in another tank)

If you can give me any help as george is my oldest Cory (4 months) and I don't really want to lose him!

The only medicine I have is white spot King British WS3 and my LFS is closed.