They were born for high flow. Their natural environment is acro colonies. It wouldn’t nip a clam. It literally can’t nip anything as it’s mouth is a tube like a straw. It doesn’t have an upper/lower jaw for opening it’s mouth. It’s really only capable of sucking (like a straw). It would pester SPS, but won’t damage it if it otherwise has an adequate food supply and is eating prepared food. They are nearly 100% reef safe if properly converted to prepared food. Here’s a view of their specialized mouth.I've seen your posts, I have a near empty 80 gallon cube style w/ sump and I want one so bad. I'm worried about it nipping an eventual clam and the SPS though. Super cool. I also run "HIGH FLOW" so that's a concern.