The typical spacing (per koiphen.com) is 30-35 gallons per goldfish. So 5-6 would be a good number if you are thinking fancy. If you are thinking fancy comets, or even regular comets, go with 4.
I keep several different types of goldfish with my koi in my indoor tank, and all do well- The only ones that did not do well were black moors.. They for some reason got eaten by my koi.. They however make wonderful tank fish, as well as pearl scale goldfish, but those are known to have a lot of health issues.
It is true that goldfish/koi do not have stomachs.. they do however have an anterior receptive sack, which allows them to hold food for a small amount of time.. it's about the size of their eye, so you could think of it as a small stomach.
If I had a 125 that was empty, and I was stuck as to what to do, I would do a planted tank with tetras, angelfish, snails, and bettas. I currently have a 30 gallon with that, and it's really fun to watch. I am looking to upgrade them to my 72 bowfront within a week or so.
But, in all, you could do quite a few things in this tank.. you could get a large fish, and keep in it.. such as a flowerhorn, or a fahaka puffer. Great personalities, and colorful as well.
I keep several different types of goldfish with my koi in my indoor tank, and all do well- The only ones that did not do well were black moors.. They for some reason got eaten by my koi.. They however make wonderful tank fish, as well as pearl scale goldfish, but those are known to have a lot of health issues.
It is true that goldfish/koi do not have stomachs.. they do however have an anterior receptive sack, which allows them to hold food for a small amount of time.. it's about the size of their eye, so you could think of it as a small stomach.
If I had a 125 that was empty, and I was stuck as to what to do, I would do a planted tank with tetras, angelfish, snails, and bettas. I currently have a 30 gallon with that, and it's really fun to watch. I am looking to upgrade them to my 72 bowfront within a week or so.
But, in all, you could do quite a few things in this tank.. you could get a large fish, and keep in it.. such as a flowerhorn, or a fahaka puffer. Great personalities, and colorful as well.




