We have a 30 gallon aquarium that my mom had goldfish in, and we had an angelfish in a 10 gallon. About 3 months ago my mom put the angel with the goldfish, and today we notices the angel fish was attacked and most her fins are gone, I moved her in with my guppys because there's more hiding spots and my guppys haven't eaten fins (I had my betta in there forever and they never bugged him). This angel fish's body is about the size of my palm, and her fins were long and beautiful :( she's my brothers fish and he's had her for over 3 years, so I'd like to try my best to keep her alive, any suggestions?

I'm taking my mothers fish away!

I do know that a 10 gallon is not big enough for an angle fish. They need the up and down room. My friend gave me her old 21 gallon high tank, and it wasn't enough room for two very small angel fish, and both ended up dying.

Angle fish are very delicate and don't handle change and stress very well. Are you sure the gold fish were eating the fins, or do you think it may be something in the water? Goldfish can live in pretty much any water, but if there was a sickness in the tank, the angle fish may not have been able to handle it.

No, my mom watched them chasing it and nipping at it. She has lived in the 10 gallon for 3 years and she's been fine... So I'm not very worried about her tank size at the moment. But I'll look into getting a new tank when she's better and can actually swim.

Or you could swap the gold fish and put them in the 10 gallon.

I have to agree with Bella. I don't know a lot about fish, but an angel fish the size of your palm in a 10 gallon tank is not okay.

My dad kept angel fish. They're mean little fish. I'm surprised that the gold fish are attacking it. Usually it's the other way around.

The one goldfish is about 6-7 inches long! It wouldn't be able to turn around in a ten gallon. But I saw a tank at the petshop here that I think would wrk great, it's 40 gallons (I think.. I'm not 100% sure, but it's pretty big) and it is an octagon shape and really tall... I've read lots about angelfish while all this is going on and I don't think she knows how to be an angelfish! She's a super friendly little fish, she hasn't eaten or attacked any of my guppys and they could easily fit in her mouth! And now I have to brag a little bit.. She does tricks :) she "jumps" for food and she eats out of your hand if she knows you! She's kind of like a dog, so it would be really hard if she was to die... Does anyone have a recommendation on an antibiotic for fish? A website said I should treat her now so she doesn't get an infection...

You should only treat fish with anti biotic if they are showing visible signs of being ill. There is a product that nutrafin makes called cycle, it comes in the red bottle. It just helps to coat the fins and protect the scales.

But if you treat a fish for an illness it doesn't have it will more than likely die.

I have bred and raised angelfish for a long time. Never mix angelfish and gold fish. First off goldfish require colder more alkaline water with a ph of 7.0 to 7.8. Angelfish are from the Amazon and require warmer, more acidic water with a ph around 6 to 6.5. Both goldfish and angelfish need room as they are both larger fish. Angels do require a high tank over a long one. Use only "Melafix" to heal the torn fins, NOTHING else.
Aurora is 100% in advising against using medications when there are no sign of disease. Melafix is a natural tea tree oil. I have seen it close up a sore the size of a dime in an angelfish in only 4 days.
If you do set up a new tank, add bacteria and cycle it for a least a week. Do not over feed as it will pollute the water fast in a new tank. You can feed every 3 days until the tank gets going.

Hope this helps you

DZGZ, thank you, I used the melafix when my goldfish jumped out of the pond. If you happen to skim through my posts in fish you'd find out my mom does not have a knack for raising fish, and I always have to help the fish she's almost killed... I'll see of we have any of the melafix left, but can I put it in with my guppys as well, if it's just tea tree oil will it effect them?

Also a little update : she's doing much better! She's swimming and eating, I did a 25% water change before she went in and again yesterday to try and keep the water clean to keep her healthy, her tail is growing back a little, the bones are sticking out still (gag) but she seems to be happier, her color is back, and her side fin finally works so she isn't flopping around.

Great. Try not to do too many water changes too often as this can add stress to the fish. 25% in an emergency is called for but thereafter 10% only. If the water is cloudy it is only due to cycling. It will clear up in a week or so, have patience. Do not confuse it with being filthy. I don't think the guppies will be negatively affected. The only time I lose small fish such as tetras (Neons and Cardinals) is when I need to treat for ich. You should be fine.
P.S. If your Melafix is pond strength make sure to adjust the amount for the tank.