After reading this and the links Tom posted I noticed one of the designs used a mess, so Iwent out hunting for some supplies and found that it seemed kinda of pricy at the moment(extra tools). So I sat on the couch with an extra pump I had and got a spong out and tied it to the impeller, Got a bucket out and stuck it in and worked pretty good till the pump couldn't get enough air and wold lock up. So I sat back on the couch and tried tieing a plastic scrubby pad to the impeller, tested in the bucket and worked. The only flaw was the scruby seemed to be falling apart the longer I ran the pump. So again back to the couch and found a old algea scrubber (one of those blue ones) and tied it to the impeller, fishing line was hard to get through this so I used a thumb tack to get a hole, this worked really well didn't fall apart. So I got out my Maxi-jet 900 and tied a algea scrubber to the blades on the impeller, just adding the algea scrubber to this decreases the bubble size by over 50%. This may not work for all pumps if their isn't alittle extra romm in the impeller space but dosn't seem like alot of scrubby is needed. I cut the scubby in half and just trimmed around the impeller. I have some expereince with fans and being unbalanced and the disc and scrubby seemed that if you didn't get the disc glued on pefectly at a right angle with the magnet you could through off the balance, so I think this way might be a bit better with no drilling or modifing the impeller. Not really sure what the size of holes in the scrubby would have on the bubble size though. If anyone wants me to post pics just shout.