I can speak to that directly. The current production method the industry uses is a batch process, whereby all your fish go into the ocean and two years later they all come out. With closed containment, if you are going to maximize your return on your capital, you have the luxury of being able to use and build your equipment so that when all the fish reach maximum size after two years--or in our case, one year, because they grow faster in warm water--then the equipment is running at maximum utility just at that point. But for most of the year, it's not running at maximum utility.
So to boost your return on your investment, when you stock the tanks with the little fry you deliberately overstock, so that when you hit the three-kilogram mark your tanks are full. Your equipment is running at maximum now for a much longer period of time, but because the tanks are full you have to take out a large percentage of the fish to allow the remaining fish to grow to full five-kilogram fish. This, then, allows your equipment to produce two harvests: three-kilogram fish and five-kilogram fish.
If you're really clever, you grade that to harvest three-, four- and five-kilogram fish, maximizing the utility out of the equipment. This is actually being demonstrated at the Freshwater Institute, which I believe you as a committee will be visiting shortly, where they have just harvested their first cohort of five-kilogram fish grown in closed containment, disease-free, vaccine-free, and chemical therapeutant-free fish, in a biosecure facility. Because the water quality is so much higher than the ocean quality, the flesh was firmer, and the condition factor of the fish showing good husbandry was superior to ocean-grown fish, too.
That's sort of a broad answer to your question, I think.