I'm wondering if anyone here has ever used a hob filter as a refugium. I have a 20 gal sump that has a very small section for my refugium currently. I have it filled with rubble rock and chaeto. My display is 90gal and I want a larger refugium for more macro algae and pod cultivation. I am considering eventually getting a Mandarin and want to maximize my pod population far ahead of time. I have an Emperor 400 that was used on my system before I added my skimmer. Now it is just hanging unused on the back of my display until I decide if it would be a benefit as a fuge. I even considered growing mangroves in it but not sure about that route. I'm wondering if it in addition to the fuge in my sump would benefit and if I need to do anything to prep it for this purpose? Or would I be better off just buying a hob refugium? Any suggestions or ideas anyone?