Older Neon sudden large lump

[shooze]

Hey guys,

I've had my semi planted tank set up for about 10 years now. Levels are constantly at 0 and the fish have been happy. I've lost a couple over the last 6 months due to old age I believe (a couple of neons around 5/6 years old (no symptoms of anything).

I bought ten new neons from the reputable fish shop near me on Thursday and as I don't have a quarantine tank put them straight in the main tank. They all look healthy.

All the Neons are shoaling together and the new neons still look healthy but a couple of the older ones have over the weekend developed a large lump. One fish is more pronounced than the other but both have it.

Any idea what this could be? I'm hoping it's not NTD. The symptoms have litterally come on in the last three days which seems too sudden for that?

 

[FreshyFresh]

It's hard to say. Any time you add new fish to a long established tank you will run the risk of bringing something in that the old stock hasn't come in contact with.

What size tank? Do you run cooler water temps? Sounds like you've gotten a good long life out of the ones you have, but it's said neons do best in something like ~68-72degF water.

 

[shooze]

The tank is a 200L Fluval Roma with a Crystal Profi 502 filter I think. The tank is actually run at 25.5c which I think is about 78f which I know is the upper limit of what they like but it's the lower limit of my German rams. I'm currently setting up a second tank which the Neons will go in which I'll run much cooler after they're introduced.

I can only assume the new fish brought something in with them. The fish with the lump still seems happy and schooling I'm not sure whether to quarantine him or not.