In my article, What's up? FLUPSYs, I explained the methods of welling and generally how they are effective as a shellfish nursery technique.
I have stated many times that there are three basic rules of aquaculture gear. There is not a better example of how those rules should be applied that with a floating upweller system (FLUPSY) and making the shift from R&D projects to commercial production. Keith Reid of Odyssey Shellfish on Vancouver Island, British Columbia has been a pioneer of FLUPSY design and experimentation. He has been producing and working with the crassostrea gigas, the Japanese oyster or giant Pacific oyster as it is known to some, for a number of years.
Keith's work has produced one of the most advanced "Commercial" FLUPSYs that I have seen to date. This is his third and largest full-scale unit. The mistakes are cheaper with smaller models, according to Keith, who used those earlier systems as learning tools. The following is a look at Keith Reid's system and how it meets the three-rule criteria for a commercial operation.

1. Invest in gear (equipment) that will last as long as possible. Go for quality.
Keith's system was not cheap to build, costing close to CA$200,000. As you can see in the photos, the FLUPSY actually looks like a floating warehouse in the harbor. The 72' x 30' structure, which weighs more than 27 tons, is framed with steel I-beams that are covered with steel sheeting. Styrofoam billets provide floatation, and the total draft of the unit doesn't exceed 4'.
Given the design and the building materials, the expected useful life of the FLUPSY is such that the amortized cost is well into the future (15-20 years). The actual payback time, however is much, much less than that and, in fact, a positive cash flow is possible in the initial years of operation. Cooperatives or larger companies could take advantage of the output of the Flupsy and the quick payback.

2. Focus on ways to reduce labour costs.
Keith claims that he can process a phenomenal 10 million seed per year-using only one full-time and one part-time worker. Labour cost per seed is incredibly low and efficient in comparison to any other system I have come across.
By having the system completely shielded from the elements, operational tasks are generally un-effected by heat, cold, rain etc. The over head internal crane system allows for fiberglass seed bins to be accessed mechanically for stocking, harvest and maintenance. The crane delivers upweller bins, which can weigh up to 800 pounds when loaded, to the hydraulically powered bin tipper. It dumps the seed onto the mechanical sorting table. Effort involved - the push of several buttons.
Once sorted, the seed is then bagged for distribution, and the bags are moved by crane to a boat for transport to shore. The tracks of the overhead crane allow it to extend out over the loading dock area accessible through double doors at one end of the FLUPSY unit. There, the bags are loaded into an outboard boat specially built with an open bow for easy access.
There is almost no physical labour involved in handling the seed during the whole nursery period. Seed, which is placed in the bins at the 2-3 mm size, is removed six months later at 17- 20 mm size.

3. Find ways to increase yield
The purpose of a nursery (the FLUPSY) is not only to produce seed as efficiently as possible, but also to condition the animals to eat constantly during grow-out.
Keith's FLUPSY is designed so that there is always a supply of nutrient rich water being run though each bin. The giant paddlewheel at the end of the structure's center sluice way keeps the water moving constantly. The paddlewheel, which is moving water out of the FLUPSY, is estimated to be able to pump 6,000 gallons per minute. With 12 upwheller bins located along each side of the sluice way, there's a potential of running 250 gallons of water per minute though each upwheller. Of course, the smaller seed would become fluidized at that volume. So, to control flow rates at each upwheller, there are adjustable flow gates between the sluice way and each bin.
The paddle wheel is run by an electric motor with both phase and gearbox speed control that allows pumping levels in the entire unit to be adjusted. The FLUPSY is supplied electricity by shore power, though Keith also has a back-up generator that is mainly used at times of the year when the unit is towed to areas that have richer waters but no shore power.
When the 17-20 mm juveniles leave the nursery, they have been subjected to 6 months of constant 24 hour per day, high volume and quality feeding. Use of the FLUPSY has not only provided rapid early growth of the seed, but it has also conditioned the oysters to be in an always-want-to-eat mode. That, combined with mid water column grow-out, allows for market ready oysters in the fall from 17-20 mm animals that are placed in the FLUPSY at springtime. Keith knows that to be true since, in addition to selling his juvenile oyster, he also has rafts where he grows them to market size.
Compare the time frame to the two full seasons typical of grow-out on the bottom or beach and you can see the financial benefits of this system. That time advantage also helps to illustrate the fundamental difference between farming and ranching. Keith Reid knows this distinction, and it is slowly being recognized elsewhere. Even if you have a very good bottom / beach grow out site, your net earning will be less.
For example, seed costs can almost double with ranching, since there is about a 40% loss of the seed planted when there's an average predation. By farming - mid water grow-out with suspended trays/cages hung from rafts - there's no seed loss, less labour needed, and better access to quality food supply to satisfy the appetite of the conditioned-to-eat animals.
If you are inclined to be skeptical, take note: "This is not theory but actual fact"
Keith's focus is on labour reduction and yield improvement. The interior of the FLUPSY unit is well organized and clean; work place safety is important, as well as the ease with which tasks can be done. All these contribute to reduced labour cost.
Unfortunately many growers, individuals or experimental groups, seem to focus on only how cheaply they can acquire equipment, and forget labour or yield until there investments and cash flows have dried up from lack of production capabilities. In the case of Odyssey Shellfish, the return on what some may class as a huge investment, is so far ahead of the industry and many other types of business operations, that most individuals just can't believe it. Even though some may claim it's impossible, good thing Keith didn't listen!

In summary, commercial-class FLUPSYs work, they are badly needed to advance the industry in many sections of the world, and this will, over time, happen.