I suppose I ought to start this post with some background on my tank and fishkeeping skills before anything else, since it's highly likely people who haven't been following my discussions on this site over the years may read this post. Tank size:
15 gallons established since:
June 2010 temp:
26 C pH:
around 6.5 kH, nitrate/nitrite/ammonia levels:
unknown since I can't afford test kits, however a dip strip nitrate/nitrite/ammonia test kit which I bought a while ago indicated zero of any of those toxins Substrate:
fairly standard gravel Decor:
2 pieces of wood which I collected myself many years ago and have used in various tanks since (after thorough boiling and washing), Lots of live plants!, Various rocks and stones I've collected Filtration:
Homemade - very, very gentle filtration made out of an airstone and some filter wool tied to the plastic insert-thingy from a breeding trap. Current inhabitants:
8 cherry barbs, 5 glowlight tetras, 1 bristlenose pleco
Some background history of my tank: Until relatively recently, I've actually been quite lazy with water changes, but having learnt my lesson and lost quite a lot of fish due to poor maintenance, I now do weekly water changes of about 25% (siphoning the gravel as much as possible at the same time), and since getting some new fish a few weeks ago I've even been doing twice-weekly water changes to offset the increased bioload.
I've had various numbers of glowlight tetras and cherry barbs for a long time now, and they have all suffered from chronic mild finrot which I can't seem to find an explanation for. At one point I noticed they seemed to get it after a water change, and realised that I was replacing the water with FREEZING water straight out of the tap which was stressing them out.
Since then I've always added warm water to equalise the temperature. I used to have to treat the tank with Myxazin in order for the fins to grow back, but since I've been taking more care with the water temperature the finrot hasn't been serious enough for me to feel justified in doing this, especially since even at half dose the medication really stresses out the fish. In any case, I've run out of Myxazin and it was very expensive, so I'm not rushing off to the shop to buy more.
However, the finrot hasn't completely abated. For example, one of my glowlight tetras has had finrot for ages (although none of the others appear to be suffering), and since I added the new fish a few weeks ago a couple of them have come down with it too. I added 6 cherry barbs and a bristlenose.
I can't think of any point when NONE of my shoaling fish have had finrot. I'm afraid this may have something to do with the fact that they've always been quite nippy, and if one of the fish gets a broken fin, they get picked on and the wound can't heal. I've discussed my fin-nipping problems in many posts on this site.
One possible reason that's been discussed is that my tank is just a bit too small for such active fish to feel comfortable in, and hence they take it out on each other. Another reason could be having too few shoaling fish; however I discovered that my glowlight tetras became much more peaceful after some of them had died, leaving a group of just 5.
Other people have told me that their glowlight tetras are just as nippy in a much bigger aquarium. I think it's just in their nature; I've noticed only the males fight among themselves, appearing to compete for dominance, while the females occasionally get caught up in a fight but rarely go looking for trouble. I've observed exactly the same thing in my cherry barbs.
Anyway, I'm starting to get worried now because I've realised the bristlenose is missing a bit of his tail, although it doesn't have the white fuzzy edge that characterises finrot, so it could simply be a tear. Nevertheless, any injury presents an opportunity for infection
What do you think I should do? Would it be worth trying to treat the finrot with medication, or should I just keep doing water changes and hope that it fixes itself up? I'm worried that the fish's fins aren't getting a chance to heal because they keep nipping at each other.
P.S. Incidentally, although I tried to pick only the healthiest barbs, two of them are 'runts' and I'm keeping an eye on them and praying they won't die, since they seem very weak despite showing no external signs of illness other than being small and scared. I'm not sure why there are always runts in batches of shoaling fish. Thoughts? Anything I can do to help them?