I´ve recently changed my setup, starting a DIY internal reactor, as shown here. So soon, I´ve noticed, proudly, that my tank was in big pearling, all fishes well and happy and so on.

A few days ago, I´ve noticed that two of my fishes had small bubbles:
A Silvertip (Sorry about the quality, but these fishes are really hard to pose to a pic)


And a Cardinal Neon



Does it happened with any of you before ?

What would be the best to do? Lower the lights? Raise or lower the CO2 injection? Wait and see?

My fishes are doing well, didn´t stopped to eat or to search for food, they are all very active, not gasping, not hide or become lonely, and are even breeding (i´ve found small fishes from Glowlight, Chocolate Neon Tetra (a.k.a. Vilma's Tetra) and Silvertips)

Regards,

Livio

The neon looks like its got Pop eye to me, and the silvertip looks like its got some kind of body fungus ulcer.

If it is that, then an antibiotic would sort it, id be suprised if it had anything to do with CO2.

The silvertip has a lesion very much like the Neon, but in other location (seems just like a bubble), but Silvertips in my tank are very active, much hard to get a clear picture.

And even when dealing with pop-up, one of the possible causes is Gas Bubble Disease (GBD).

Gas Bubble Disease

Algone.com - Fish Diseases

Flippersandfins.net Pop-eye article

Of course, I will treat them as a regular disease - already isolate them at Hospital Tank, some antibiotic and so on. But even it they get better, I may not be sure about the diagnostic, as when I change them for another tank, surely it will not pearl, and then I will be treating the GBD too.

So, I ´ve bring my question to share with you guys...

Regards,

Livio

It's not due to CO2 gas or O2.

If you had 10C or lower temperature and 1.5 meters depth, then you get issues potentially like that.

Regards,
Tom Barr