calico fantail needs your help

Question
Hi Stephanie;
Thank you for quick response.After I put this question on-line, I had a close look at this calico,it looks like the other two fish somehow have bitten the calico's back fin, this is why he swims awkward and stays at bottom corner most of the time. Any suggestion? Thanks again in advance.
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-----Question-----
I have a calico fantail little over a year companied with two other regular red fantails. Last couple of days I noticed he is staying at the bottom of the tank most of the time, his fans are in dropped motion and swims awkward. I have changed water , and filter regularly. The other two are fine, I don't know what is wrong with calico. I need any help I can get to save him. Thank you in advance.
-----Answer-----
Hello,

This could be a water quality problem or an internal infection. You should check your water for nitrites and ammonia first, to make sure that is not the problem. You can buy test kits to do this, but some pet store will also do it for you if you bring in a water sample.

If it is an internal infection I recommend treating your tank with a product called 'Maracyn-2'. This is an antibacterial medicine specially made for internal infections.

I hope this helps.

Regards,
Stephanie

Answer
Hello,

The only thing to do about aggresive fish is to seperate them. Continue observing your fish closely to see if they continue to be aggresive towards each other, even if their territory is established. If they do you may need to move the aggresive one to another tank, or return it to a pet store. You should also add some aquarium salt to your tank to help your calico's fin heal.

Best of luck!

Regards,
Stephanie