Gsp And That White Goo

I have had a slight revelation this evening with my GSP; it has shown 4 polyps and they are flowing in the current. The thing which shocked me was while mixing salt staring into the tank wondering what was going on the GSP fired a plumb of white goo up towards the surface of the water. There were loads of white particles floating around the tank for a good few minutes afterwards. Here is the question: what the hell happened? Is this the coral sporing or is it this digested particles or is it waging war on the other occupants? The clown fish certainly didn't like the taste of it he seemed to shake his head from side to side and looked like he was shuddering afterwards has he kept on opening his mouth really wide. He is good now eating anything that floats by. I have attached a picture of the corals so that you get an idea of distance between them. I would be very happy to hear what people think......

Regards