My tank is killing bettas...

[davebarrett]

Ok, I have a twenty gallon community tank. Until four weeks ago it consisted of:

3 neon tetra
6 glowlight tetra
3 clown loaches
6 guppies
1 Betta

For some reason around three weeks ago my betta (which had been in the tank and quite happy since it's installation several months ago) suddenly died. I got back one afternoon and it was lying on the bottom barely breathing - it didn't survive the rest of the day. I could see no obvious sign of disease, and none of the other fish are showing any problems at all.

Next thing, I find a little baby guppy swimming about. Uch, not only am i not particularly enamoured of guppies, I certainly don't want little ones, so I gave them all to my sister so that I could get more interesting fish.

I settled on Honey Gouramis, and bought five. One died within a day (stress, I think), the others have been settled now for two weeks. Last week I decided to replace my betta (the LFS had some gorgeous red ones that I couldn't resist).

I got home this afternoon to find my betta covered in cotton-like growths, and obviously in a lot of trouble. It was fine yesterday - when I fed it and the other fish frozen bloodworm (thawed, of course, but this is the first time I have ever given them frozen instead of live - I have been unable to find live food for a couple of weeks now). Unfortunately the betta died very quickly earlier today.

Now, I have been watching all my fish very carefully, and monitoring the water (which is high on nitrate due to my water supply - I am gradually changing to mineral RO water from my LFS), and none of my other fish are showing signs of stress, disease, or unhappiness.

What on earth could be killing my bettas?! I know gourami are related to betta, and they have no problems so far (you wouldn't believe how often I am checking them!). The only thing I can think is that there may be some remnant of whatever killed the last betta lurking in the tank - but if that is the case, it must be something that only affects bettas.

Anyway, that is my problem. I would love another betta, but need to find out what the problem is (or whether I could just have got two bad fish...). I don't intend to keep buying fish just to watch them die...

Any help appreciated!

 

[fourplayfishy]

are you getting lathargic ones at the lfs or the really really lively flaring ones?

 

[davebarrett]

I didn't pay much attention to the first one, but he was certainly lively in the sense that he was always swimming around the tank and regularly made faces at me when I went over to watch him. When he died I looked at a lot of info from sites such as this to check I hadn't done anything stupidly wrong, and couldn't see that I had.

The second I got I made sure that I looked at all of those available carefully, and did pick the one I thought most lively. And for the first two days in my tank it went up and down the glass making faces at it's reflection... think it figured it out after that and chilled!

It was lively up until today...

 

[kev_kb]

Could it be stress related? I'm only a newbie Betta keeper but I thought you weren't supposed to keep them with Guppies or Gouramis?

 

[davebarrett]

I discovered that they shouldn't be with guppies, which is why I removed them. Didn't see anything that said about gouramis though... I guess this could explain it. Stress could have made it susceptible to whatever disease killed it.

If that is the case, I guess no more bettas for me until I get another tank...