Aquariums need aeration.
Because aquariums require aeration, a variety of pumps are available. One pump--the hydor ario pump--is available as a built-in aquarium volcano ornament. The volcano hides the silent pump and red LED lights create a volcanic glow from the mouth of the volcano while the pump blows up a continuous stream of air bubbles via a filter sponge.
Troubleshooting Your Aquarium Volcano
If your volcano is not producing air bubbles, there are a few simple things you can check. Make sure the air tubing is properly connected and is able to draw air from the surface. Look for any kinks in the line that can be causing an air-flow blockage.
Check the air-control valve on the pump and make sure it is open and not closed. You use this valve to adjust the air flow. The valve may be open, but set too low. Try opening it wider.
Lastly, make sure the filter sponge is not clogged with algae. If it is, remove it, clean it and replace it. Now see if air bubbles are able to flow through the top of the volcano.
If none of these things appears to be the problem, then you will need to replace the pump. If the pump cannot be removed without damaging the volcano, you'll have to replace the volcano unit itself.
Tags: filter sponge, make sure