[canadawest]

Simon, I know that Seacare orders Mazzeii venturis all the time, as well as the Kent ones. J&L also stocks the Kent ones from time to time, but last time I checked they only had a 1/2" one left and the Berlin skimmers use a 3/4" thread for a straight replacement.

I have seen Seacare's HUGE skimmer and Tim runs it with dual 1" Mazzeii venturis. The Mazzeii venturis are about twice the price of the Kent venturis but apparently produce more bubbles.

I think for a smaller skimmer like the Berlins though, a $30 Kent replacement venturi is good enough. Discussions on Reefs.org and Reefcentral.com mention that people who have replaced the RIO 2500 pumps with a Mag7 or Mag9 and added the Kent venturi have observed HUGE performance improvements on their Berlin skimmers.