SPS aggression /compatibility?

[PotatoPig]

Is there a guideline on which SPS can be in close proximity and/or touch?

I have an “SPS ridge” that currently holds a stylo (forest fire), a blue branching digi, and two acros (purple, frog skin). They’re starting to take off, especially the digi, and I’m now realizing I didn’t leave as much space between them as I probably should…

So I recently moved the purple Acro from the digi (digi was almost in contact), but looking ahead I’m wondering which of these will be ok in proximity? I see a lot of pics of SPS tanks where there’s a ton of SPS almost on top of each other, so am assuming/hoping some are ok?

 

[Waters]

Acros will pretty much kill other acros unless they are the same species. The tanks that have crowded colonies are constantly pruned or the owners just let them compete to the death. I have had to shut down a couple of SPS tanks due to neglect in keeping colonies contained.