What Delphinus said reminded me of an article I read a year or so ago, basically... a 2mm grain of sand will support different life than a 2.5mm grain, some of the things we are trying to keep like a very very specific size of particle... I wish I could rememer where I read that, Oh hang on.. brain storm...
http://www.animalnetwork.com/fish2/a...wb/default.asp
http://www.reefs.org/library/talklog...ek_090698.html
http://www.animalnetwork.com/fish2/a.../1/default.asp
Couple of links to read and consider.[/url]