Urchin troubles

[Sushiman]

I have a blue tuxedo for about two and a half years. He is a huge part of my tank's clean-up crew, tank stability and an ample source of greens seem to have kept him happy & healthy. I have never seen him in an idle state. He always seem to be feeding. Before my recent struggle with Bryopsis I regularly fed him Nori, now I do no direct feeding other than the odd bit of greens from the fuge. He seems to be making a real dent in the Bryopsis, I've recently purchased a second Blue & a brown spiky bugger to keep him company & attack the remaining weeds.