In-Tank Electrolysis?

[ubiq]

I have this knock-off submersible 13 watt UV sterilizer completely submerged in my tank. Whenever I run it, it creates microbubbles even though there's no air reaching it. Does this mean that stray voltage from the device is electrolyzing the water?

 

[lapin]

Are you sure you have purged all the air from it?
Sometimes there are pockets that get trapped

 

[ubiq]

As sure as I can be. Also, it ran for 24 hours fully submerged. Hard to believe there would be any residual trapped air after that long.

 

[DCR]

It is more likely trapped air or the heat from the UV is causing some degassing of dissolved air. I am pretty sure electrolysis would require a DC current through the water. At least that is how it is normally done.