Sprung Stunner danger level

[sgdcover]

Hi everyone,

I'm considering adding a Sprung Stunner to my 28 gallon Nano. Truth is I don't have much room left, but I'd like to try keeping one. My worry is regarding the tentacles that come out at night.

I've searched everywhere and although there are many references to the tentacles and the fact that they can hurt nearby corals, I couldn't find more specifics. I have three specific questions:

1. How dangerous are they? Not too bad or will burn anything around it?

2. Are there specific corals or coral types that can tolerate it's tentacles?

3. How much room should I give the Sprung?

Thanks again!