This is from the previous post like Recty mentioned.
"Ok, I will post on my personal experiences. I acquired a blonde naso that was raised for 5 yrs entirely on romaine lettuce. He is a beauty and grew at a great rate while in his care. I never knew of using romaine until buying this fish from a fellow reefer.
I have 13 tangs and feed them 4 huge leafs a day along with 4 sheets of nori a day. I have had all my tangs over three years and am proud to say they are beautiful. My growth rate is crazy. All fish have double and even tripled in size. I feel after 3 yrs of success of feeding romaine, I can honestly say I couldn't imagine not using it. It works.
I don't steam or anything. I just clean and throw in the tank.
If my personal experience don't help you. The georiga aquarium feeds romaine and broccolli daily to its reef tank."