problem with Aquafuge....microbubbles.

[Skeptic9962]

cant seem to find much info on this topic so i figured idd ask and see if anyone has ever had this problem....i just got a small CPR aquafuge from a fellow reefer and on his tank there was no bubbles at all but as soon as i put it onto my tank and turned it on it started putting out microbubbles where it comes into the main tank.anyone know why this would happen i did clean the bubble bag just rinsed it out cause there was 2 snails that had crawled into it....about a day ago could that have anything to do with it?

any help/advice is helpful

thanks

Dan