its generally not wise to mix too many anemone species in the same tank. they are quite intolerant of each other. and does not matter how far away from each other, as long as in the same water bodies, they can interact with each other with chemicals. but this is just a textbook literature example and should be followed with a pinch of salt and used as a guideline, for i have seen numerous occasions where reefers have proved against this.
technically, its true. so just run carbon and regular water changes should work.