Just for the record air bubbles will not kill a fish. Think about the billions of fish that live in the surf where there is far more bubbles than a air stone. Or for example what your display looks like if a powerheads begins to vortex and shred air into the water column. Or a return pump section that hasn't been topped off or is cavitating. Or the fact that they are common in freshwater tanks because they don't need the kind of flow we do and freshwater fish are just fine with there use, yet marine fish would die? Logic tells us otherwise. Aquarium myths that won't die hard.