I have oranda gold fish with swim bladder problems. I got 11 baby orandas last summer for my 3200 gallon koi pond from 11 very small babies 6 of them survived and now they're pretty big: probably 4'' and some even bigger they're a probably a year and a half or 2 years old now. 4 of them survived thru the winter just fine in the pond along with the koi but 2 of them didn't do too well at the end of January and i had to bring them inside. They did very well for couple of months since i took them inside. I don't have an aquarium, so i kept them in 8-9 gallon plastic container with the heater and air pump. No filter but changing 75% of water every day: (always monitored the water temperature so only changed water with the same temperature as in the holding container) and full water change weekly. The problem is that one of them still doing very well at this point but the other developed swim bladder problem and had been swimming upside down: belly up for about a month now. I've tried some steps: withhold the food for 3 days and then started to feed them defrosted peas with no skin for over a week already. Still no change in the ability to hold himself in normal swim position. I feel bad for poor fish: he's very active and absolutely doesn't look like he's dying or even sick: i actually have been hand feeding him peas because i don't think he can get food on his own as he has trouble swimming to the bottom. He's very exited every time i come to feed them and gladly takes peas out my hands. Just not sure if that swim bladder problem could be cured. Is anything else i can do for this guy? The other fish is doing great and i actually released them both back to the pond as the temperature of the water is warmer: always above 60 (around 70 (20C) in the day time and little less about 63-65 (17-18C) at night. I made small inclosure with plastic net as i don't want this poor guy to be wondering upside down in big pond with no ability to swim normally. Also i have ability to hand feed him in this inclosure. Should i stop feeding them peas and just give that medicated food instead? I attached the picture of both of the fish i kept inside in the pond now. Any suggestions would be appreciated.