Need some help with a Red Sea Nano setup

[Swaefa]

I have purchased Red Sea Reefer Nano (21 gallons) soon. Given the small size of the sump (7 gallons), what protein skimmers would you recommend. I am concerned about the availability of space. I may add other devices at a later date such as reactors and want to make sure everything fits. Do you have any hacks for the Red Sea Nano sump to build a refugium or attach? 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 for your help.

 

[Broadfield]

I haven't noticed many owning the Nano, but the Reefer specific thread I started would be a good place to ask... and also to share your setup as you progress.

https://www.reef2reef.com/threads/show-off-and-discuss-your-red-sea-reefer-series.219309/