Just wanted to let people know, I got the 250 model last week and it is AWESOME!!! In 2 days it started accumilating lots of dark brown gunk. It was easy to set with adjustment like the ASM's, came with 2 590 GPH needle wheel pumps air and water silencers. I really like this unit and it was not over priced, just thought I would pass on the info for anyone looking for a good quality mid priced unit.