Newbie question on filter bubbles

[kniveswood]

I got a Jepo in-water filter. I noticed that if I position the filter near the water surface, it starts blowing bubbles. And if I position it lower, there are none.

Which is the correct position?

[vinz]

Both. If you want bubbles, position it higher. If not, then lower.

I'm guessing your filter has a venturi. Normally, the venturi is a short length of pipe placed perpendicularly upwards of the outlet. When the water flows thru the outlet, air is drawn down thru the venturi and exits the outlet as bubbles.

Some brands come with a cap of sorts to cap the venturi when you want to use it near the surface but not want the bubbles.

The venturi is designed to aerate the water, where needed.

[kniveswood]

I see. Are there any pros and cons to having bubbles or not?

Like fishes less likely to jump? Or better oxygen? Healthier water?

[vinz]

Depends on the type of tank.

In a fish-only tank, aeration is good for oxygenating the water.

In a planted tank, the bubbles will remove the CO2 which the plants require. So, it's bad thing. The plants are providing the oxygen, so aeration for that purpose is redundant.

[kniveswood]

Thanks a lot for the advice! ^_^