I have one. It's been running about 3 months, at its highest setting. It feeds its bubbles into a converted EV 180 because (a) I had an unused EV180, and (b) I needed something to fit in a low, small sump. This modified EV 180 has a standard 1 inch inlet, with no insert. The air supply lever is turned off.
The eheim is totally silent and rock steady. It produces almost as much skimmate as the EV180 did when set up conventially with a 900 gph pump feeding the standard air injector venturi, but it is much, much quieter, more stable in its output, and uses about two thirds less electricity. I have nothing similar to compare the new eheim with, but it seems to me to do a super job, considering it is part of a 'jerry built' combination. The unit as a whole is probably a bit undersized for the fish with live rock and all kinds of inverts 220 gallon aquarium it's skimming, but it steadily produces almost a pint of dark tea skimmate most days, and is part of a filter system that includes lots of live rock, a wet/dry filter, a small sunlight fueled algae/caulerpa garden, Polyfilters, etc. It would produce a darker skimmate if I let it, but Evs tend to gunk up. The tank's fish include a 6 inch Bigeye Catalufa, a 4 inch Cowfish (both caught here in NJ), a half-grown Spotted Drum, a mated pair of Perculas, a pair of two inch Blue Chromis, and a few other odds and ends.
Compared to other things I've seen, the Eheim produces lots of very fine bubbles effortlessly, with no fuss, noise, vibration, or other issues. It is unmodified, right out of the box. It seems like it should last indefinitely. I think it's terrific, and I know that it would really work extremely well were it connected to a more appropriate skimmer. It is a quality product and completely trouble free. Easy to adjust, and maintenance is a breeze.
