Why are my fish attacking each other?

[DreaminginBlue]

Please help- four candy cane tetras.
Yesterday I noticed one of them chasing another. Thought they were playing. Apparently not. This morning saw one harassing another and the poor guy had a huge white patch that looked to be exposed flesh where his scales got ripped off. His dorsal fin was torn as well.
Why is this happening? What can I do? The aggressor seems to be bothering others as well. They aren't sick, are they?

 

[sinibotia]

Getting more candy cane tetras would likely help. In schooling fish any aggression will be dispersed through the school. How big of a tank is this? Can you describe the white patch- is it fuzzy at all?

 

[DreaminginBlue]

Okay- cycling is why I only have four. 26 gallon planted tank, though my plants seem to not be doing great. As far a so I can see it isn't fuzzy- it would be strange if they were sick because I just finished a five day dosing of medicine because I was afraid they would get sick when one of the platies the store gave me died of an apparent disease. Seems there is one fish being a meanie but I can't tell for sure. Going to run to the store and get a breeding net to put the sick one in. How else can I help him?

 

[sinibotia]

Could just be stress from the cycling water parameters combined with low numbers. Might be best to isolate the aggressor as well as the injured fish.

What kind of medicine? Fish get all kinds of diseases and just like with human medicine there is no treatment that works on everything. It's entirely possible to get one disease while treating for a different one.

As far as helping the injured fish, I would just isolate him and keep an eye on him, unless you have a separate cycled tank you can move him to (I'm presuming you don't). He should heal on his own- but if anything else comes up (especially if any fuzz appears on the injury) then you may need to take more action.

 

[DreaminginBlue]

It was supposed to be for everything- Tetra LifeGuard. Going to get multiple chambered breeding net ASAP. I hope he isn't sick.

 

[sinibotia]

It was supposed to be for everything- Tetra LifeGuard. Going to get multiple chambered breeding net ASAP. I hope he isn't sick.

As in most things in life, if it claims to solve all your problems it's probably a scam The closest thing to a cure-all for aquarium fish diseases is actually just plain old salt, and even that will only get you so far.

The active ingredient of lifeguard is actually effective against quite a few different problems. That said, there are plenty of things it doesn't help with. I would be cautious using it without knowing with some certainty what you're treating.

I think the injured fish will be fine. If it starts growing fuzz on the injury, then it's time to do something, but fish are pretty resilient

 

[DreaminginBlue]

Thank you for the help. I have aquarium salt and if needed I will put it in. Now I have to catch the stubborn little guy, and I discovered in a planted tank with rocks and stuff for him to hide behind, it's pretty difficult.