Thanks @Mattreslooks like a type of Tubipora musica. If it is it will have more of a calcareous skeleton than GSP. I received some Tubipora musica about the size of a 50cent piece from an online vendor as a throw in and instead of throwing it out i put it in the back of the tank. It quickly grew quite large so in that regard it can quickly take space you might want for other corals.
It grows quite interestingly and adds some depth to the back of the tank so I've kept it but if it were close to other corals it would need frequent pruning i think.
Sorry just had another look. No skeleton base.looks like a type of Tubipora musica. If it is it will have more of a calcareous skeleton than GSP. I received some Tubipora musica about the size of a 50cent piece from an online vendor as a throw in and instead of throwing it out i put it in the back of the tank. It quickly grew quite large so in that regard it can quickly take space you might want for other corals.
It grows quite interestingly and adds some depth to the back of the tank so I've kept it but if it were close to other corals it would need frequent pruning i think.