Here are some predators you can look at:
Fuzzy dwarf lionfish...Dendrochirus brachypterus
Fu Man Chu lionfish...Dendrochirus biocellatus
Dendrochirus zebra (Dwarf Lionfish, Dwarf Zebra Lionfish)
Parapterois heterura (Bluefin Lionfish, Blackfoot Lionfish)
Spiny waspfish...Ablabys macracanthus
Cockatoo waspfish...Ablabys taeniantous
Longspine waspfish...Paracentropogon longispinus
Sailfin waspfish...Paracentropogon sp.
Whiteface waspfish...Richardsonichthys leucogaster
I kept a predator (FOWLR
) tank before, most of these guys are small but are messy and require heavy filtration and biweekly water changes especially with such a small tank if you plan on keeping 2-3 predators.
These fish stay relatively small 6 inches or less but are messy tank inhabitants.
Here are two links to a website that specializes in these types of fish. The owners have their own forum and can be easily reached for questions.
direct links: https://www.lionfishlair.com/care-guides/lionfish/