Bubbler in Goldfish tank?

The first possibility is supersturated gases. My water is BAD. If you notice bubbles on the walls of the tank after a water change, you've got some. If you have a filter on your house, you've got more. If you use a Python water changer, you have even more. If this is the case, age your water with an airstone for as long as it takes to remove microbubbles. I'd recommend adding a powerhead at the surface to help with gas exchange. It would also be a good idea to do 2 water changes/week at 50% rather than the big one.

Next we have carbon dioxide. It can rest at the bottom (especially if your tank is tall) and at the surface. To resolve this, add a weak powerhead at the bottom of the tank to force it up and out. It can also rest between the lid and surface if you have a lid. If you do, remove the lid permanently. Even then, if your water is below the very top, blow a small fan over the surface to remove the build up and let oxygen through.

You can add a bubbler, but keep in mind they do almost nothing to oxygenate the water. The bubbles themselves don't oxygenate. It's when they break the surface that gas is exchanged. It's like poking a pinhole in a brick wall lol.

Some fish are more sensitive than others for various reasons (genetic, past illness). I have a fish with her gills turned out. As she has grown, it has gotten harder for her to breathe. Take a close look at your fish to check for any abnormal physical traits.

If you really want to geek out like me, order a Salifert Dissolved Oxygen test. It is for saltwater as well as freshwater. It will tell you how much oxygen is dissolved in your water for your fish. You can find charts online to tell you how uch oxygen your fish needs by type and size. That will let you know right away if it's the water or the fish.

It's so frustrating when you are doing everything right and still something is off. It took me a year of watching my fish gasp before I figured out the problem with my supersaturation. If you see bubbles in the poop or slight popeye, these are the first signs of gas bubble disease.

One more thing, don't underestimate the power of the gill fluke. They cause breathing issues once they establish themselves in the gills. Flukes are in every tank, all the time. I treat my fish for flukes once a year. I also treat every new fish while in quarantine. It's like deworming a puppy. Very gentle. I'd recommend you do 4 rounds of Praziquantel just in case. It will keep the population in check and help the affected fish if it is flukes. The Prazi won't hurt the cycle or the fish (even if they don't have flukes).

Good luck!

Do you normally feed floating foods? If so it might just think it may get fed and see if there is any food on the surface. How cool is the water? Warmer water carries less dissolved oxygen.

Hmmm... the only other thing I can think of is to increase the surface agitation, but it sounds like there should be plenty of that already.

Goldfish are really oxygen greedy, but as you have a 4 feet tank, you dont need one. with 4 feet you have enough of the oxygen that diffuses in to the water in the surface so you wouldent need one.

I have a 3 inch comet goldfish that lived in a bowl with no extra oxygen until I got a better tank for it.

My friends gold fish loved the bubbler!!

She would play in it all the time and shake her tail:)

I think a bubbler in your tank would be a great idea:)

And I good way for your fish to get more oxygen

I had a bubbler in my tank

But took it out because my fish didn't really enjoy it that much

But it sounds like a great idea for your gold fish

Best if luck!:)

Hey, once me and my dad went into petco because my fish were all dying, and an associate told us that despite the name, goldfish don't belong in bowls, they belong in an aquarium with proper filtration. Take this as you will, but if you're having a problem I would convert to an aquarium with a bubbler.