ok filtration know-alls. so i got a lil bored today and started doin some research on refugiums. i'm not super familiar with living filters so maybe someone on here can throw me a bone. is it benefitial to have a refugium on a freshwater tank? if so how big does it need to be? what would be better to keep, inverts, plants, mixture? i'd like to try it out and see what happens but help me out please.