I keep my Mandarin with Magnifica, Gigantea, Malu, Crispa, BTA and Maxi Tapetum. I have not keep them with Haddoni yet. I have never lost a Mandarin to these anemones. I can see that there is a risk with Haddoni but no personal experience. So far my Mandarin have no problem with a large Gigantea, 12 inches in diameter, in a small 18X20 tank.