Another dwarf neon rainbow not doing well - discolored spot?
Sorry to keep posting, but just wondering if anyone with more expertise might know what the problem is - I posted several days ago about a new dwarf neon rainbowfish not doing well, and now another one seems to be going the same way - hanging out near the surface, seems weak. I noticed what seems to be a discolored spot on its back and am wondering if that might help to figure out what's going on? I haven't had this type of fish before and don't know how they normally look, but the other ones don't look like that.
Tank parameters: Ammonia 0, nitrites 0, nitrates 10, temp 78, pH 8.2. 45 gallon tank set up about a month; did fishless cycle using old media and began adding fish last week. Aquaclear 70 filter. Other fish: 8 cherry barbs, 1 angelfish, 4 other dwarf neon rainbows, all doing well.