I've got a gourami that's been steadily going downhill. It started becoming listless, and hanging around near the top of the tank gasping a few weeks ago. I assumed there was an oxygen issue but did a water test on all the usual factors and everything was fine, and in addition all the other fish are showing absolutely no problems. Since then it's just got worse and the last few days doesn't seem to be able to do much other than lie in one position, not moving and gasping. Also it's slightly swollen... but I've seen much worse on another fish which had dropsy once (and recovered), so I don't think it's that. We were about to euthanize but I figured I'd try a forum for any suggestions first. Unfortunately I don't have a quarantine tank if it turns out that it needs treating with a medication separately from other fish. Any thoughts, or is it just time to put it out of its misery? The tank's due a water change, so I'll do that tomorrow but if it shows no signs of improving after that, I don't really have any ideas as I can't work out what the problem is.
Tank details: 0 nitrite, 0 ammonia, 20-30 nitrate, 30-40 litre. Other fish include 5 danios. ph is quite high, but has always been high as it's just my tap water. Only recent change was newly added plants a couple months ago (though that was a little while before fish started showing symptoms).
Tank details: 0 nitrite, 0 ammonia, 20-30 nitrate, 30-40 litre. Other fish include 5 danios. ph is quite high, but has always been high as it's just my tap water. Only recent change was newly added plants a couple months ago (though that was a little while before fish started showing symptoms).