I've decided I wanted to do an HOB refugium for a 20g tank for copepods. I checked out YT for videos and seen some people had rigged a large breeder box with an adjustable air pump. Has anyone tried this? I found a large one for 0.5g but I feel like I would need two of them to get a decent collection. I was planning to use my 5g to culture as well. Is the 0.5g too small for a 20g or would it be better to get two of them in addition to the 5g? If you haven't used a breeder box, what else can be used besides buying a refugium?

