Mouse,
Read that thread I posted at the top of page #2 of this thread. I've posted my thoughts why the filter works. In a nutshell, I believe the bioballs act as a nitrate factory (break down tank waste in the water column) and that combined with a heavily laden iron substrate and phosphates from the food we feed promote Caulerpa growth. It seems that when nutrients are in the proper ratio that nuisance algae growth is minimized. There's a paper by Colins on The Krib (
http://www.thekrib.com) in the Freshwater Planted Aquaria archive that goes over this in detail.
I really do NOT like the use of Caulerpa in this "filter" because of it's tendency to go "sexual" (i.e. crash) and the problems with it attaching to the substrate (I'm still trying to tear this %$#@ out of my display tank). I think if you're going to use this "filter" that you should use other macroalgaes like Chaetomorphia sp. that Midland Marine, Marine Ecosystems, and Inland Aquatics sells. Good stuff, grows fast, won't go "sexual", doesn't attach, grows dense and harbors a LOT of critters, etc.
I do believe it is exporting nutrients in the form of caulerpa, but my concern is what effect the iron in the substrate (a terrestrial element) is having on the system as a whole. I asked Eric Borneman what his thoughts were on some of the "effects" seen by people on their corals that they ascribe to the MM filter and you can read the results here:
http://www.reefcentral.com/vbulletin/showthread.php?s=&threadid=39436 Heh, I wonder if Leng's following these threads... [img]images/smiles/icon_smile.gif[/img]
liquid