Lesion? Ulcer?

[Bobo8]

Just noticed today my fish has a lesion on him. I was only home for a minute so
I put melafix in. It's a rasbora. I tested the water and
Nitrate 10
Nitrite 0
Ammonia 0
The water is a little basic but has been for years. No recent changes or anything. Sorry the pic sucks they didn't turn out well.
I know the pic makes it look fuzzy but it isn't. It looks more like an ulcer?

 

[Bobo8]

I noticed another one of my fish has a lesion/ulcer as well.
Here's a pic.
Again sorry it's so bad. I couldn't get a good one. But that white spot is on him.

 

[Caliban07]

Hi bobo.

My first port of call when my fish get any disease of some kind is to up my tank maintenance for a couple of weeks.

Gravel vacuum cleaned filter pads (in removed tank water) and water change. 2 50% water changes a week with dechlorinated water.

Is there anything that external or internal to the tank that could be causing stress?

What is your ph and the temperature of the water.

What kind of test kit are you using?

 

[Bobo8]

I did the water changes.
I use API test trips
And the temp is about 28
I can't think of anything that could be causing stress.. No changes in the last 2 years. My rasbora ended up dying the next day but my neon is still alive and he is declining. There must be a medication I can use?

 

[Bobo8]

I think he also might be getting dropsy. Here's a few pics
Sorry they are not the best

 

[Delapool]

Could be a bacterial infection like columnaris.

Also worth getting a liquid based test kit. I use the strips sometimes but any hint of a reading I go back to liquid based as the strips can under read.

http://www.americanaquariumproducts.com/Columnaris.html

Edit - I'd QT those fish ASAP if you can.