Has anyone ever seen "blisters" on the dorsal fin of their guppy before?
This guy is over two years old, maybe close to three years old and is the only guppy in a moderately planted community tank right now.
Ammonia - 0
Nitrite - 0
Nitrate - about 30ppm
GH - very hard
Total Alkalinity - 180?
PH - about 7.8
Temp - about 80