So, I have been planning a build for a while now, and I am at a bit of an impasse. The plan is a 40B with as large a sump as I can fit. Most likely a 20L or I may do a DIY custom job. Problem #1: I want a mandarin. I have heard this is too small a tank to keep one in, especially if not trained for pellet foods. Problem #2: Can a horizontal style ats (algae scrubber) grow pods? Or would a DIY HOB fuge work better? Both would most likely waterfall back into the tank. Problem #3: Say I wanted to use both an ats and a refugium. Would I then have the ats in the sump and the fuge hob style or vice versa? I expect some flames coming at me simply for wanting to keep a mandarin in a 40B, but please understand that if it would be detrimental to the fish, I will not bother pursuing it anymore.