For awhile I thought mazzei was a big hit. A few months ago when I was restarting my tanks, I found mazzei threads on quite a few forums (namely planted tank and the barr report) and I thought it was universal. It basically uses a venturi to cause a quick compression/expansion of the water, something about torrents, and crushing the co2 bubbles into micro bubbles, which collect on the plant leaves. I believe it is a more efficient way of injecting co2, since rather than floating up and outgassing, the bubbles float around for awhile (they don't float up noticeably from what I've seen on videos).