Please Help! Goldfish is sick and Iím not sure whatís wrong
I have 2 commet goldfish, I purchased them around a year ago from our local pet store.
They are in a 190L tank and have always been very healthy and active, they have grown significantly in the year Iíve had them and theyíre beautiful.
Parameters in tank are currently;
Nitrates 20-40 (closer to 40)
I clean their tank once a fortnight and maintain a clean tank.
Around 2-3 months ago they encountered fin rot, I treated them successfully with melafix as I caught it in the very early stages thankfully.
We have now encountered a very mysterious illness and I canít put my finger on what it is or how to cure it! Driving me mad!
1 1/2 weeks ago one of the goldfish started to bloat but only on his left side, he was still eating fine but started to low down in activity.
His scales sightly distended on the area that was bloated but nowhere else, which was so confusing as I considered dropsy but thatís usually the whole abdomen that gets affected not just one side.
I did a 30% water change and decided to start dosing with melafix until I could get to my local aquarium. I fed a deshelled pea to help clear him out in case it was some form of constipation
I did 2 days of melafix before noticing he significantly deteriorated, he began not wanting to eat, very inactive and just hovering around in one spot just over mid point in the tank and he had swelled up heaps, his scales had started to rot away in the area where the scales are distended, it looked like it was being eaten.
The next morning his scales on his left side were very Ďrawí looking and the scales on his left side had also started to distend and swell, they also partially looked like they were being eaten. He also developed a red lump on his top dorsal fin? I was stumped!
The parameters have remained stable this whole time.
The local aquarium believed it may be a swim bladder infection eating its way out of his body, they have prescribed Bactonex and see if that helps, 1 dose wait 5days then another dose, as per the bottles instructions.
I performed another 30% water Change as instructed by the man at the aquarium. His tank friend is still not showing any signs of illness?
My goldfish is still not improving and still deteriorating!
His swelling has gone down a little bit and the red lump on the dorsal fin turned white but his scales on both sides are slightly raised still on the patches that are red and raw, the redness is darkening but still spreading. He has also now got a red blister like patch on the top of his body near his dorsal fin that looks like itís oozing white stringy stuff, the scales on that side also look as if they are oozing white stuff.
He is eating very small amounts and spits out most of it. He is still just hovering around mid point of the tank, his tank friend is still unaffected and is leaving him alone completely.
What do I do? Iím going insane trying to figure out what exactly he has, whatís caused it and how to cure it!?!?
If anyone has advice please help, Iím desperate to cure my Nemo!