[edmondspl]

I know that coral should be placed about a foot apart. But are there any types of the same famely or so that can actually touch without killing each other safely?

[Reefland]

Yes some corals do touch and will not cause any problems, but this is an exception and not the rule. Corals need room to grow and without the room they will often times compete in chemical warfare to protect their existance.

[BubbaWPB]

I have frogspawn (Euphyllia divisa) and hammer coral (E. ancora) adjacent to each other without problems. But I hear that torch coral (E. glabrescens), even though it's the same genus, is not a kind neighbor to it's relatives.