Is there enough oxygen?

Question
Hello, I have a 36 gallon bow front with a 55 gallon biowheel,media,mechanical filter. Two aerators, and heater set at 72. Stocked with 1 three inch ryukin, 1 three inch oranda, and 1 1/2 inch fantail. I feed green peas, red flakes, frozen brine, orange slices, and pro gold pellets, a different food every day and enough for them to consume in 30 seconds. I do a 25% water change every two weeks and add fresh water weekly. My water test perfect most of the time. My question is why do the two larger goldfish go to the top of the tank for one to two minutes after they eat, taking in what looks like to me, Oxygen. They will do this off and on for about 30 minutes after they eat. then afterward settle on in for there daily swim. Is there enough Oxygen? Thank you for helping me solve this issue.  

Answer
Hello Linda-

Goldfish are notorious for gulping air when they eat food from the surface, so the behavior you are seeing after the feeding is probably the fish trying to "burp" up the air they have swallowed.

It's normal; otherwise your goldfish would keep the air in its stomach and develop bloating and swimbladder problems.

If you notice any other strange symptoms though, it could be a sign of blockage. Watch them carefully and feel free to write back if something's not quite right.

Hope this helps,
Amber Worman