They’re stilled systems. No circ reefs. Not with sps, but you’d be amazed at the fare that will handle stillness and microcurrents (movement still occurs but slower) such as mushrooms, briareum GSP, some palythoids will tolerate it as well though they don’t maintain the low hydrodynamic profile.
https://www.pjreefs.com/
Paul is a legit guy I knew him before these systems at nano-reef.com in the biotopes forum, he was working with stilled systems and I hadn’t thought that was possible at the time. The live rock he sells for the systems is quite nice it’s not barren