I will be buying a Red Sea Nano soon. Given the small size of the sump, what protein skimmers would you recommend. I am concerned about the availability of space. I may add other devices at a later date and want to make sure everything fits. Do you have any hacks for the Red Sea Nano sump to build a refugium or has anyone done a HOB to the sump? Also I will be replacing the ATO with a Tunze ATO. Not sure if this information would influence your recommendations on the refugium or protein skimmer. Thanks