I purchased 2 x Hillstream Loaches and a small Oranda from a local LFS
(that I have never used before but have quite a good rep from what I can gather) - brought them home and got them settled in to my tanks (Oranda in one tank with another small Oranda that I already had and the two loaches in my larger tank - already has one small loach, a few oranda and some gold minnows).
Noticed yesterday (Sunday) that the oranda had an odd white mucus type coating all over its body - it was just sitting on the gravel and not doing very much at all.
Both loaches had a white coating over parts of their bodies (could just about make out their markings).
This evening when I returned home from work the Oranda is about the same - not eating, not moving - when caught in net it didn't move or flap - just very slow breathing...
Both Loaches were dead - they had gone nearly totally white (I can upload a pic if it will help).
I have tested water and both tanks are: PH 7.4, Amm 0, Nitrite 1ppm, Nitrate 5ppm. All of my other fish are fine, the other loach in my tank is also fine - skitting around as usual, no discoloration etc. Same with the rest of my fish - all are absolutely fine - no visible disease, all eating and swimming as normal.
Now the fish that I bought were kept in separate tanks that I would assume are all linked through one large filter/sump system in the shop - is it possible that they were all carrying some form of disease and introducing them in to my tanks has brought it out? Should I start dosing my tanks with medication to make sure the rest of my fish stay ok?
Any help or advice would be great as I obviously don't want to lose any of my other fish!