Goldfish Not Growing?

I have a little common/comet goldfish ( I would estimate 2 1/2 inches) living in a 115 gallon aquarium. It has enough filtration for a 200 gallon. A close friend of mine won him at a carnival, then decided she could not take care of him so he was brought to me. I got him last June, and he was been living in the 115 gallon for 10 months. Though, I have not seen him grow at ALL. It has been a year and absolutely no growth. Recently I added a second goldfish to the 115 gallon, and this one is already growing in the short time I have had it. So now I am concerned about the one who hasn’t grown in a year. Was he so severely stunted in the short time he was at the carnival that he will never exceed 3 inches? My new goldfish is pushing 8 inches, with room to grow. I would be very sad if the 2 1/2 inch goldfish never grows again. Thoughts? Is the 115 gallon too small for him to grow larger? He looks soooooo small in it.

 

Hi, a 115g tank shouldn't stop it growing at all as you've found with the other goldie, are you sure it's a common / comet?

 

Definitely think he is a common.
Here is a picture. His tail is disproportionate to his body, I believe because of stunting.

 

did his tail always had the black tips? I think in time he can grow bigger.

 

This picture is from a few months ago. The black tips were healing from ammonia burns. He is all good now.

 

I took him out to take pictures today. The last pic was taken right after I got him last June. There is no change in growth. Though he is a lot fatter and more orange now.

 

He likely wouldn't have gotten stunted for the short time he was at the carnival. They usually pick up feeders from the pet store a day or so before the carnival.

The black on his tail actually looks natural, its not uncommon for comets to have black and "Grow out of it" basically. It doesn't look like ammonia burn or anything to me.

He should be fine and growing. I don't see any physical signs that would worry me. Just keep feeding him a high quality diet and making sure the tank is nice and clean

 

Though he is a lot fatter and more orange now.

that's a good start, gotta get healthy first.

 

A larger goldfish can cause the smaller ones in a pond or aquarium to stunt- esp if he’s already 8 inches! There is also genetics and epigenetics (like maternal effects) that could be at play. (A runt) Stunting isn’t normally permanent ifprovided with hormone free water though but I wouldn’t worry since he looks healthy and well fed. I agree those don’t look like ammonia burns on the tail . Signs he’s still young . He probably likes the giant tank you bought for him lol.