| | Dropsy Outbreak
Hi, I have a 100 gallon planted tank with a school of 12 cardinal tetras, 3 rainbow fish, and 4 zebra danios.
My tank has only been set up for about two or three months. I used the bio media from my old tank, so the tank has never had any ammonia or other measurable toxins. Nitrate is at 20ppm. PH 7.5 My substrate is boiled miracle grow topped with gravel.
Last week I noticed that one of my Cardinal tetra's had developed dropsy (scales sticking out; looked like a pinecone). Then another. Now a third. The Cardinals seem to be the only species affected (so far). Strangely, their appetite and activity does not seem to be affected.
The only information I can find suggests that I'm probably not going to find any obvious answer. I don't really feel like throwing a bunch of anti-bacterial medication at this without even knowing if that's the problem.
Perhaps someone can suggest a plan of attack? Or some sort of direction I could take? Should I remove the sick fish?
Any pointers would be appreciated.