With live rock in your refuge ou probably already have those critters in your refuge you just might not see them yet. Worms and Pods
are good for your refuge. Not much more will be overly desirable as the hole point of a refuge is to provide a space wher eyou can cultivate something with out the problem of it being eaten or prayed upon.
If you dont see very good growth outof the algae then you might need to up your light intensity. If you do this going to a reverse daylight cycle on your refuge will probably be of benifit. For example if your lights on yoru tank come on at 11am and run till 11pm then have yoru refuge come on at 11pm and off at 11am. Lighting it 24/7 could cause problems. Make sure it does not go sexual. If the algae goes sexual it can kill water quality very fast as it relases its spores.
I think algae starts to turn white when its nearing this point.