Air leak through impeller seal?

[legion]

I have a close loop setup that is producing microbubbles. I have tried sealing the intake portion of the plumbing and resealing the plug in my dart. I have also tried reducing the number of outlets and the output flow to see if the pump had any cavatation issues. I have also let the pump rest to remove air from the housing.
SO, at one point I had salt creep around the impeller shaft, no longer. Can the pump even pull air through the seal? Not a huge deal, after years with my tanks I must have a million powerheads. But a problem, none the less.
I intend on keeping it off and check for salt creep elsewhere, but don't believe that to be the case.

 

[legion]

bump

 

[pbienkiewi]

fill the tub up, seal off all holes but one to blow into it. Rap the holes up with tape or something to seal off any small holes, Put it into the tub and blow into it to see where the air bubbles are excaping from from. Find them and seal it off.

 

[acrylic51]

You could be drawing air into the lines anwhere you have made connects (glue joints) etc.......Where are you drawing your water from for the Dart.....I do know and have seen that if it's drawing to fast and the water level is rather low it will induce air bubbles........

 

[legion]

Actually when I took the pump off the impeller was clogged with with a bunch of mini snails and my smallest hermits. When I take it off I have found some, but never this many at once. Time to redo the intake strainers with smaller holes.
Thanks,