from reef to fowlr need quick tip

[manaf]

so i shut down my reef tank sold pretty much everything except the sand, lights, skimmer, powerheads, and the tank.

so i cant stand of having no fish atm so i wanted to setup a low maintenance
tank with only a couple of eye catching predator fish that i couldnt have in my reef .

thing is i dont want just rocks and sand i have seen ppl have some types of seaweed in their tank , so what im asking what is their i can add that gives more life but not technically corals thx