Lonely Angel

One of my goldfish appears to have been attacked by the others. When I woke up this morning I saw a goldfish in a hollow ceramic log tecoration and I thought perhaps he'd died. I netted out the log but he was still alive. He's not in good shape though, his tail fin is in shreds and the back part of his body is all raw - all the scales gone with just raw flesh left. When I found him the pleco fish was in the log behind him so I don't know if the pleco did this to him or the other goldfish did and he swam into the log to escape.

Right now he's just drifting in the water looking dazed, and the other fish are occasionally coming over and nipping at him. I'm going to get him a 10 gallon tank to keep him in so the other fish aren't attacking him any more, but what else can I do?

And now as I'm watching them I see them all going after another fish. What can I do to stop this? Please help me I'm worried about my fish.

sirdarksol

I would suggest getting some vitachem for your injured goldfish, and if you can find it, OmegaOne goldfish food. The improved nutrition will help your fish heal. An isolation tank is an excellent idea, and will keep him from being further injured.

As far as stopping the attacks, I have an answer, but you might not like it.
Unfortunately, a 55g tank just isn't big enough for the fish you have. It's about big enough for four of the goldfish, and that's about it. I'm not going to go into this too much, since I'm guessing it's already been discussed in the "fish acting strangely" thread.

With regards to the attacks, the fish are feeling cramped, and they're in polluted water (with that many fish, it would take about a day for the water to become unpleasant to them). Pretty much all animals (humans included) respond to conditions like this by becoming violent. This is a matter of population control. The biggest and strongest ensure that they survive while the weaker are left by the wayside. In nature, the weaker animals will respond by trying to relocate. In an aquarium, this isn't an option. They have nowhere to run.

I would suggest finding new homes for five of the goldfish, the koi, and the pleco. This should ease the stress on your fish and they will be more content to live together.

susitna-flower

In addition to the suggestions sir had for you, a treatment you might want to use is metafix. This should help heal your fish also.

Bottom line is that your tank is overcrowded. Even two the same size won't take care of it.... You need a pond, and turn your 55 into a tropical tank...

Nags1965

I was also told by the place I got my fish that turning the tank lights off when the fish seem stressed is a good idea. I am really a beginner when it comes to fish and tanks so I have no idea if this is good advice or not. It seems reasonable to me though.

Halibut

Thats the 1 time one of my fish was killed was when the lights were off.

Ntruder1400

It may be wise to put the injured fish into a breeding net or other isolation device within the main tank until the 10g hospital tank is cycled, Putting an already weakened fish into an un-cycled tank may do him in.

Nags1965

turning out the lights may not be such good advice..

COBettaCouple

Can you get Fish Protector and Vita-Chem? They'd help with the healing process in a hospital tank with water kept extra clean.

jamison

My boys were raised carnivore and would bite each-other when they ran out of live food, leaving some really nasty battle scars. My fish guy suggested a few tablespoons of aquarium salt to heal the wounds and reduce the stress, so I tried it and it has worked wonders! Their fins grew back almost instantly and they are far less aggressive. If you buy a bottle, it's not only cheap, but has specific instructions, even for goldfish! I hope this was helpful to you!

sirdarksol

Good point. Goldfish usually respond well to medicinal salt. However, this can only be done as salt dips or in the 10g hospital. The pleco won't like salt added to its home, and could die from it.

Lonely Angel

Thank you for everyone's suggestions! I put in a tank divider so the injured fish can be kept separate from the others. I also got the 10 gallon but I'm not using it since he's looking pretty weak and I don't think he'd do well in a cycling tank.

I was able to find the melafix at petco but I didn't see any of the other products so I'm going to the locally-owned pet store today to see if they carry them. If I find the salts, I can move the pleco into my turtle's tank while I use them, but how long would I have to wait before he can be safely put back into the fish tank. I'm assuming the salts will stay in the water for a while, right?

I will get another tank and find homes for the koi, since I want to do everything in my power to keep this from happening again. Unfortunately, a few days after I got the aquarium my horse became very sick and needed surgery, so the vet bills are leaving me with a tight budget right now. I'll try to get another tank as soon as I can though.

Lonely Angel

I'm afraid I have bad news. Bellman, the injured fish, died this afternoon. He had been gettng weaker all day until he passed away a few hours ago.

Ntruder1400

My condolances.

jamison

That makes me so sad. I'm so sorry!

COBettaCouple

We're so sorry you lost him.

sirdarksol

Sorry for your loss.

Depending on where you live, a temporary option for the koi would be to get an extra horse trough and keep them outside (I saw a 100g trough at Menards for $40 today). You'd need to get an extra filter for them, and they would need all of the normal care like water changes, and would still eventually need a larger living space, but it would at least give you a few months' time to get something figured out. You would want to keep the "pond" in a shaded area, and you'd want to put a screen over it (too keep the koi in and fishing critters out).