Betta's Fin Ripped

HI everyone,
About two weeks ago I got a male halfmoon betta fish. He is in a 9 litre (2.37755 gallons) tank that is both filtered and heated to 26 degrees celsius. About a week ago I added two white cloud mountain minnows. Recently I have noticed my betta's caudal fin becoming ripped. I think it was already becoming ripped before I added my minnows. I think causes could be the minnows nipping, tearing on a rock he hangs out in or something like fin rot. He is my first fish, he's very social and I would hate for anything to happen so any help would be appreciated.

Thanks

 

Honestly the tank is way too small for the minnows let alone minnows and a betta.

 

Oh ok. What about tail tho?

 

I hate to say it but 9 litres in way to small for those 3 fish, is there any way you can either return the minnows or get a larger tank for them.

Also have you tested your water parameters (Ammonia, Nitrite & Nitrate) as I suspect your tank is probably not cycled and the Ammonia is causing your bettas fin rot. Until you can sort the tank size issue you will need to do lots of small temperature matched water changes with conditioned water.

 

Hard to tell what happened to it but really clean water is usually the best treatment.

 

possibly take out the minnows if you can (get a new tank for them or sell them or something like that)
in my experience the Bettas tail has grown back on its own once he wasn't so stressed out.

 

Ok thanks everyone. I haven't tested water because I don't own a test kit. I can try to get a new tank for minnows or my friend can take them. So just water changes?

 

Lots of small water changes for now, I would do something like 25% daily to keep the Ammonia and Nitrites down if I were you and once the minnows have been removed he should slowly get better. If he doesn't improve you will need to add medication, there are mild options to treat fin rot like methylene blue which can either be used as a quick dip or applied directly to the fin rot using a cotton wool bud/q-tip or there are stronger meds meant for treating fin rot that you can get at most fish stores or on Amazon. I would also strongly advise getting a water test kit as soon as you can!

 

Just did a 25% water change and am trying to relocate minnows

Thanks so much for the help everyone. very quick replies