Spots on coral
I am new to the forum I've had a 150 gallon that I purchased used and stocked pretty well. Just had a water change levels are all good 4 t5 lights but I'm seeing brown spots on one new coral I put in last week. Teck said not to worry but I am any help would be appreciated. The rest of the tank looks great but I'm also noticing these little blue starfish are they a nusance?