I have kept dussumieri before and will first off caution you that this is a species that is active and gets large fairly quickly so be ready if you get one. Juv and subadults are basically grey, around 5-6" color starts to develope and starts to becomes breathtaking above 12". Feeding and behavior is pretty standard as with most acanthurus tangs. I would say they fall on the hardier side on the family. They prefer strong current so provide good water movement. I looked that you have a 225, be aware that this is a minimum and I would consider a larger home down the road if you choose to keep one. This are great fish except for the size they reach and the speed they reach it.