so I've heard before about swim bladder disease, from bubbles

[Magnum Man]

I would say this is highly oxygenated water... the tank obviously needs filling, ( it's about 4 inches from full ) too busy right now... but with the Tidal hang on back filter, when the tank water level gets too low, they suck air and it gets whipped in the impeller, and looks like this... I've never had swim bladder in this tank, though I hate to admit, this is when this tank gets maintenance... and the filter makes a horrible sucking noise in this state, but this is one of the tanks in the mud room, which we don't spend any time in, I won't let my other tanks go this low, the noise would drive me crazy... but I'd say, at least this water is very highly oxygenated...

 

[AJ356]

Not quite the same, but the closest thing that this reminds me of, was when I had a load of Bentosi tetra (similar to Rosy Tetra), and every now and then one would start to move funny, increased twitching and repetitive movement. Not quite a full swim bladder difficulty, but possibly having gulped in too much air when darting up and feeding from the surface. The problem would always resolve within a few hours, or by the next day.

 

[GaryE]

There are fish that live in bubbles, at the base of rapids and in rough water, and fish that don't. The swim bladders takes their air from the gut, and in effect, our beautiful fish are balanced by unused farts. Nature is beautiful.

How much air can get down past the stomach into the intestine? I have seen fish burp, which I've always figured took care of most gulped air. But if I do a water change in the coldest part of winter, mixing hot and cold water to get the right temperature but still dealing with oxygen super saturated water from the cold (If it's -25 or colder outside), fish can have buoyancy issues. It isn't a loss of balance and rolling as in swim bladder damage, but it is dangerous for some of them as they zip, stop, zip, stop. Those dead of winter bubbles make me skip water changes til things improve outdoors, and the fine bubbles stop coming from the tap.

I'm thinking those tanks deserve more attention, even if they are full of fish from the Congo River rapids region (which seem happy not far from torrents of bubbles)!