Female Betta killing other fish in tank

dark crystal

Hi, I'm hoping other more experienced aquarium keepers can help me!

We bought a new 30 litre aquarium before Christmas and having cycled the tank for 10 days, we bought a female Siamese Fighter fish and 3 Neon Tetras. Next morning, the tetras were dead - one was actually missing!

We left it a week to replace them and added another Female Siamese, but the original Betta is constantly attacking her. The guy at the pet shop said female Bettas generally co-exist peacefully, but this one a vicious creature and seems not to want any other fish in her territory.

Has anyone any ideas on what fish we could try to introduce to the tank without casualty. It's very upsetting to lose fish like this and we don't have a separate tank in which to place the original female.

Thanks.

Silverfish

Neon tetras are a shoaling fish, and need to be kept in groups of 6, so they're not a great idea for a 30L tank.

Bettas are a solitary fish, males and females. The females are generally more peaceful, so some people can keep them in a community tank with no casualties, but these tanks would usually be quite large and the betta would still keep to itself. In a 30L tank, she should definitely be by herself.

dark crystal

Thanks for that. Looks like we're going to have a pretty empty aquarium for the time being so!

She's managed to kill the second Betta now, so I'm not going to chance any more fish in the tank with her. I honestly had no idea the female would be this aggressive.

Silverfish

They have different personalities, some are very chill and some want to murder everything. But if they feel threatened at all, it's full attack all the time.

Some bettas live quite happily with shrimp - could you try cherry shrimp?

I was creeped out by them at the start but then I got some and I loved them, they're fascinating to watch, they're incredibly busy all the time, and they have a lot of babies so that's always fun too.

dark crystal

Yeah this girl is a full on psychopath by the looks of things!

I haven't seen any Cherry Shrimp in the pet shop I bought her from, but there's a Maxi Zoo near enough to me, so I might take a look there tomorrow.

Thanks a million for the advice - better than any info the pet shop assistant gave us anyway!

Knine

Have you a picture of her? I brought a female and had her in with a lovely full finned male. The next day the male was dead. It turned out that my female was actually a short finned male. The females have an obvious to the eye egg sack. Google it to see the location so you can check.

A 30 litre tank is only suitable really for one Betta. It is certainly not big enough for Tetras. Most Tetras need a well established tank to survive. Did you test the water?