mushrooms getting longer

I'm new to LED lights. I was told to start low and work my way up with my coral. I only have three small guys, two mushrooms and a star polyp.

When I bought the mushroom it was about 1 inch around and flat. Now it has a smaller head and an elongated trunk/body. Is this a sign of too little light?

parameters are amm 0, nitritie 0, nitrate 10