How much space does a Bubble Coral need around it

[Oscar72]

So I have what Id say is a pretty big Bubble Coral roughly the size of a softball. I just moved a Hammer/Frog S. about 4 inch above it. Thoughts?

 

[declanisadog]

I would keep an eye on it for a time. They have pretty long sweeper tentacles, and I’ve found mine had won against any other coral it’s cone in contact with.