Got a deep sand bed… what do I use it for?

[Alpha_and_Gec]

I recently added a significant amount of sand to my aquarium to hopefully boost biological filtration. What do you guys reckon I should use the sand to keep? Garden eels and jawfish are out of the question, but maybe large watchman gobies(yellow watchmen are too small)? are there rays small enough to go in this tank? Perhaps a horseshoe crab would appreciate this?

80 gal reef, currently stocked with anemones, 2 hermits and a damselfish. Going to get more coral this week. The sand is new and a mix of live/dead, but is not currently very bioactive.

Maybe I can get a bobbit worm and have it build a burrow that coils around the entire tank… would be silly.

 

[Pickle_soup]

From what I gather, horseshoe crabs prefer cooler temperatures and they don't do well in reef tanks.

 

[Mr. Mojo Rising]

It looks like 2”-3” of sand? Looks like normal amount, not what I would call a “deep” sandbed. Any sand sifter would be a fun addition, a pistol shrimp perhaps?

 

[Alpha_and_Gec]

From what I gather, horseshoe crabs prefer cooler temperatures and they don't do well in reef tanks.

Carcinoscorpius rotundicauda(one of the species I’ve seen for sale) exists within a subtropical - tropical range. They are unfortunately too big… unless partially amputating its telson deals no permanent damage to the animal.

 

[Alpha_and_Gec]

It looks like 2”-3” of sand? Looks like normal amount, not what I would call a “deep” sandbed. Any sand sifter would be a fun addition, a pistol shrimp perhaps?

there’s another inch or two hidden under the white ledge. It’s about a quarter of the way up my rockwork, although no measurements had been done yet.
plus it’s deeper(albeit rougher) at the back to provide a sleeping space for wrasses.

A big bullseye pistol would be nice.. unfortunately they’re still pretty small. I’m afraid if I add an eel or some other predator it would pick em off.