Odessa Barb With Recurring Dropsy

1 of my Odessa barbs has had dropsy twice recently. The first time was in July. I noticed it a bit late but managed to get him into a tank with epson salt. This last week the same fish got dropsy again, but I caught it a lot sooner so he's doing fine again. I'm confused as to why he keeps having this problem. None of my other fish have been sick since this started and I've not noticed him getting picked on. Anyone have an idea as to why this is happening?

 

How often and how much are you feeding? What are your parameters? Photos?

 

I feed them twice a day and only enough that they finish it within a minute.
Ammonia: 0
Nitrate: 10
Nitrite: 0
I do a 25% water change every weekend. There's nothing to photograph since he's doing fine now. He's just swimming around with the other barbs like nothing happened. I just want to know what things could be causing this fish to keep getting dropsy when the other fish are doing fine

 

Dropsy isn't a disease, but a symptom. It appears when a fish is having kidney problems, and can no longer maintain the balance of water inside and outside its body. It begins to fill.
It can come from simple, treatable problems, but can also be a sign that an individual fish has an internal problem, with its kidneys. Here, I find it is often the end stage with fish that are very old. It can be as simple, and sad, as an individual which has developed kidney problems.

 

Yeah your probably right, but I'm a bit confused as to how the epson salt treatment has worked both times if his kidneys are not working and as to why the two times would be so far apart?

 

Oops double post

 

The Epsom salt actually acts as a bit of a diuretic. So it flushed the excess fluid out of the kidneys. Which decreases the amount of work the kidneys have to do.

Have you tried doing a dewormer? The underlying cause may be a parasite that is inflaming the intestines. Which will inflame the swim bladder, causing the dropsy and increasing the load on the kidneys..