Host animones are from several different evolutionary lineages, but, all require full strength salinity of 35 to 37 ppt, and temperatures of 81 to 84 degrees F (27 to 29C).
Dispite the fact that they have zooxanthellae and require or prefer bright lighting, all host anemones need to be fed and will do best with one, or a pair of clownfish, However, the size of the clownfish needs to be tailored to the size of the anemone.
A moving or unattached anemone is an unhappy anemone and is probably not long for this world. unless conditions are changed. Conditions that may need correction might include: food quantity, food type, current, substrait, or light intensity (too much or too little). Be sure all powerheads and water pumps intakes are carefully screened to prevent accidential injury to a roaming anemone. Tanks with large heavily fed anemonies must have excellent water flow and agressive protein skimming. hope this helps. research the specific anemone you are considering and make sure you can provide the correct environment for the animal and proper care. good luck on your project.