Bully goldfish

[Akalei]

I'm new to owning and taking care of fishes. I got 4 goldfish for Christmas. 2 little black moor fishes and 2 small fantail goldfishes. We had 1 black moor fish died a few months back (i do not know how) and a few days ago the other black moor fish died. I had noticed a week before he died that he was swimming weird. He had no side fins (were they had been eaten) and one of his tail fins had been bitten. Today we noticed that our half gold half white color fantail has been swimming the same way the black moor was. wobble swimming and floating. We also saw that our all gold fantail was chasing him. Now we know who our bully fish is but we do not know what to do. If you could please help us with our Betta and our Fantails that would be great. Oh I also forgot that our fantails are in a 10g tank. Thanks in advance.

 

[Chrisk-K]

So, are those goldies in a 10g tank? What are the water parameters? What filter are you running?

 

[Akalei]

Yes they are in a 10 gal tank. They are small fantails.. about 2 inch in length, from head to tail. The filter that we have been using is Aqua-Tech 10-20 power filter. I am sorry but I do not know the water parameters. Like I said I'm new at having an aquarium.

 

[Reframer]

So the problem is that they do not have adequate space and the bioload is too large for that tank. You need to upgrade your tank if you want to keep them. You need at least a 30 gallon for 2 goldfish. Fins were likely missing because of fin rot caused by poor water conditions, which also likely killed the others. Goldfish need extra filteration because they poop a lot.
Either you have to get a much larger tank and filter of you must return the fish and pick out some others, it will not work in a 10 gallon (sorry for the disappointing news).
Have you been changing the water at least 1 time a week with dechlorinated water?

 

[Akalei]

I do not change the water,but my boyfriend does change the water when need be. My boyfriend got these goldfishes because he had had fantails before. But I don't know how big of a tank he had. I will tell him the information that you guys have given (i thank you both).

 

[Jill-O]

I love goldfish! We have three goldfish tanks right now. One problem with them though is they need a pretty big tank. They're so personable and cute. Good luck with yours!