Posted by Mark024 on February 21, 2003 at 20:26:49:
In Reply to: wet dry and reef posted by urozero1 on February 21, 2003 at 17:12:37:
Well there is some debate over this... you see a wet/dry filter does a fine job of removing wastes and providing an area for nitrifying bacteria to turn the ammonia into nitrite, and the nitrite into nitrate, but that is the problem- there is no way to provide for the anaerobic process that breaks down nitrate, so essentially the filter becomes a nitrate factory. This is fine for fish only tanks because nitrate is generally not toxic to fish, but its effects on corals and other inverts can be debated. As a result, there are people who use a wet dry anyway and count on water changes to remove the excess nitrate, and there are those who prefer the "berlin method." The berlin method is a means of biological filtration that is capable of bringing nitrates down to zero. Basically, all you need to do is provide a sump with a strong protein skimmer (I suppose it could be done with a hang on model, but a sump is always helpful), which will help remove wastes before they become ammonia, nitrite and nitrate, and provide a large amount of live rock and live sand. Live rock has deep pores which serve as a site for the anaerobic bacteria (which break nitrate down into nitrogen gas and oxygen gas) to grow and break down the nitrate in your tank. A filter is not needed, but some people perform basic chemical filtration in the sump with carbon, phosphate removers, etc. Taking the biological media (like bio balls) out of a wet dry filter will set up a similar (though more expensive) system. Once again, the keys to a berlin method tank are strong skimming and live rock.
-Mark
