The only natural host for maroons is the BTA. Fortunately, they are one of most common host species and the easiest to care for. You want a well established tank in very good condition, as anemones are much more demanding than clownfish, in terms of water quality. If you're new to anemones, do lots of research before selecting one. Getting a healthy one to begin with is important. Anemone proof your tank before adding one, put covering on any intakes, as BTAs will wander around until they find a place they like, generally a cave in the liverock.