Tiger Barb Question

[booboo22]

I had a tank with 3 tigerbarbs and 2 swordtails. The tigerbarbs have been there for about 3 months and I recently purchased the swordtails. Everything was fine for about a week...

One day I noticed that one of the tigerbarbs was dead. When I was netting him out, I saw that another was also dead, but this one had his stomache eaten out. Now I'm not sure how normal that is, but they had all been fine just a few hours before.

The next day I noticed that my velvet swordtail's tail was a little shorter than it had previously been. Upon further inspection his pectoral fins were shortened, one being half the size of the other, and he was also missing many scales towards his back. I put him in an isolation tank, but he died shortly after.

All of this happened in a matter of 2 days...

So finally, my question is... What caused this sudden change in the tank? and how can i prevent this in the future?

 

[Fishyfanatic]

How long has the tank been setup?
What are your current water parameters (ammonia, nitrite, and nitrate)?
Any new additions to the tank?
What is the size of the tank?

 

[booboo22]

The tank has been setup for just over 3 months. It's a 5 gallon, and nothing has changed except the addition of the swordtails. And as for the parameters....?

 

[Fishyfanatic]

That's the problem. The Tiger Barbs need a larger tank than a 5 gal. Even 1 in that tank is too much. The Sword Tails also need a larger tank. To prevent it in the future, purchase a larger tank. 29 gal minimum. The barbs are more aggressive in nature than the swords. This could be why the sword is missing his fins.

Don't feel bad. This is common for newbies. Just an excuse for you to buy another tank. In case you haven't found out, we encourage more and more tanks.

Do you have a test kit?