Goldfish Sick, Floating, Need Help

Hello,

I need some advice and help with my goldfish. I have 4 goldfish (3 orandas and 1 ryukin) in a 40g hex. They have been in this tank for 3 months and are going to be going into a 120 gallon within the next 3 months when I move to a larger apartment.

They have been doing great. Then yesterday, I notice one of the orandas has developed what appeared to be a case of bad swim bladder which isn't unusual. I gave them some lettuce for roughage / fresh food as that seems to help when they show swim bladder symptoms. The fish was staying at the surface and when it would swim down into the water, if it wasn't deliberately trying to swim it would bob back to the surface. She seemed okay otherwise. Sometimes while at the surface she would roll to her side a bit.

It was the same this morning. But since I have come home from work, she seems pooped out and is staying at the surface, on her side, not moving apart from her mouth, tail hanging sort of limply. She is alive and her mouth/gills are moving like they do, but she isn't moving the rest of her body. I have looked at her very closely and her fins have a sort of wilted look to the very tips. She is a white fish and her fins are mostly clear white, the wilted looking area at the very edges looks milky and maybe a bit slimy.

What can I do? Is there something I should treat the water with? Please help, I'm very attached to her and want to do everything I can. She's my favorite fish. =/

The water has had a partial water change. The other fish are acting absolutely normal and fine.

I have not tested recently. I will. Yes, it is entirely possible the other goldfish might have nipped her fins. I had thought about that. I have fed some lettuce, I don't have peas or Daphnia. I have some moss/algae growing wild in another tank I usually throw in for the goldfish when it needs cut back. I can throw some of that in.

Back again, it does appear that she has been nipped twice at least since I have been home although I did not see any fish in the act of doing so. She has a red spot on one fin and another by the base of her tail that looks like a bite. These were not here a bit ago. However, she has started moving more, even swimming some and being more upright. The temp on the tank is up a bit since the water change I did earlier... its hard to have enough cool water.

Oh and to answer your question about the tank, yes it was cycled and is not a new tank.

I have been feeding Omega One goldfish flakes as the majority of the food but also some live or fresh plants from my other tank or lettuce or bits of apple. I'll get some peas asap. She is still having plenty of troubles, but is better than she was. At least she is staying much more upright just under the surface of the water instead of laying limply on her side. She is also moving her fins and even swimming a bit. Perhaps she just got really exhausted from trying to swim downward or fighting the current of the filter when she has too much air to go where she wants to go... then got nipped a few times because she was lying like a dead fish. Its a theory anyway.

I just finished the testing.

Ph 6.6
Ammonia 0
Nitrites 0
Nitrates <5 - a hair lighter than the 5.0 color on my comparison card.


I did not test prior to the water change I did earlier, so perhaps the nitrates had gotten too high. Should I let her rest or should I do another water change right away?