I was selling the big one not to long ago. But I could never get it off the rock. Not even during the tank transfer from the 180 to 300 did it move an inch. I've had both ritteris for more then a year. They could b a whole lot bigger if I feed them. But I don't. I use to feed them a lot. The purple one was 3" when I got it. Now it's easily 12 to 14". They are pretty hypnotizing to watch when there's good current. But u do need to be carful with big nems they will eat small fish. I actually had my banggi cardinal die yesterday (I think from old age, cause nothing was wrong with it and all other fish are fine) but it was free nem food. Let's just say I have no frozen fish in my freezer just nem food.