I'm working on a high protein food product that can feed millions if cultivated correctly. thats why i need a souce of fast growing seaweed since seaweed is mostly protein and 99% digestable.
What is your source of information for the statement that "seaweed is mostly protein." I am pretty sure that for most plants, this is incorrect.
Biolante is a fast-growing seaweed, big, too, but hard to control.
Frankly, if you want to develop a food from the sea to "feed millions" I'd go with salps. That or figure out how sea turtles do so well on jellyfish.
Of course, if you're looking to cultivate Soylent Green, look no further than your own kind...