BTAs like krill, not that mushed Hikari crap, but actual whole pieces of krill (e.g., San Francisco brand). They also like fresh shrimp from the seafood dept. at the grocery store. They also like fresh scallop, again from the seafood dept. In addition to those items, I feed mine squid (San Franciso brand), occasional wild-caught salmon (when I cook some for myself). BTAs, I find, to be good eaters. Feed small pieces, no larger than a green pea. Keep your water parameters in good shape. I just use API tests, which are not super sensitive from my understanding, but my nitrates are always at 0 on that (probably not literally because chaeto grows fast in my tanks). I would suggest a temperature between 77-82F. I believe what Ron Shimek states in his little book on keeping host anemone species, that "full-strength" sea water ~1.026-1.027 with an accurately calibrated refractometer is very important. I don't believe anemones care particularly about Ca or Mg, and I never worry about that or test or dose it. The more you feed, the faster they grow. If you want a really fast growing BTA you can feed a little several times per week, but once or twice a week is plenty, too. And, if you never directly feed, the BTA will stil be fine and grow very slowly.
