Help, whats the deal with mud filters?

[i like fish]

hi, i found these, and i was just wondering whats the deal with them, are they useful, or good, or any ideas at all ? all opinions appreciated, thanks

 

[i like fish]

http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=8181&ref=3055&subref=AC&N=2004+22778

forgot the link, oops

 

[seafan]

Sounds like a refugium filter. The Idea is to grow calpura to eat up nitrate, have LR to eat up nitrite , and have 'pods to eat up organics. You could also put in a skimmer, or so the caption says. If you put some lighting on it, it sounds like it could be a decent(great) filter. Let us know how it works out.