The first thing to do is replace the air stone or bubble wall. Or clean it out. Depends on what it is made of and how old it happens to be. These clog and need frequent replacing or cleaning. The second thing to check is the tubing. Airline tubing tends to oxidize at the sight of the port and become stiff and restrictive. Remove it, snip an inch or two off, and re-attach it.
If these tips don't help, check the rubber diaphragms inside the pump. They have to be replaced every year or two like with any pump, since they are made of rubber. Because of this, we do not cover them under warranty but do sell the repair kit separately.
If the issue is a crack in the housing or armature, etc., then this would be covered under warranty if you ship the pump back along with something showing the original purchase date.
Date published: 2019-07-18