Refugium critters

I have my refugium going now and it is doing great....at this time I don't have any critters (other than pods that hitched and or came from the tank) in there. Do you need anything in there like snails, hermits, stars, or whatever is needed? If you do have critters in there what are their purpose? If I am fine as I am or if I need to add some critters either way is fine.....I would just like to know for sure. I have heard and/or read where others do have them but I couldn't figure out why.

 

I have 2 kinds of snails, cerith and nassarius to keep the 4 inches of sand stired up plus a couple of hermits that weren't behaving in the main tank (knocking stuff around). I might add a crab (emerald, sally... etc) in the future to help keep the macro in check but im not at that point yet.

Marc.