They have 2 sizes that I am aware of. The first is the one I have, it is rated for like 90 gals and I run it on a 29 and I don't feed anything but zooplankton and phyto. So I really don't have any excess nutrients because I do 20% water changes once every two weeks and it still pulls tons of gunk.
Then they have a larger unit that is rated for like 200 gals (I think) Both seem to be well made, and are very nice. Oh yeah, BTW, little to no bubbles enter back into my sump.