TABLE OF CONTENTS Pages Symposium 1 - the National Sea ...

media. The water enters the filter near the bottom and flows up through static bed of
filter media and exits by gravity through a slotted pipe near the water surface. The filtered
water flows from the solids filter by gravity into a moving bed biofilter containing 1.0 m 3
of the Kaldnes biofilter media. A 1.25-hp low-head centrifugal pump returns water to the
culture tank. A more complete description of the system can be found in Van Wyk
(2000).
The initial capital investment required to purchase the land and build the facility was
$533,500. An additional $212,500 must be spent over the ten year life of the project to
replace worn out equipment. The model assumed the facility was built over a three-year
period, with four greenhouses put into production in each of the first three years of the
project. Each greenhouse cost approximately $35,000 to set up. This included the cost of
the site preparation, greenhouse kit, construction labor, electrical installation, tanks,
filtration equipment and a blower. The well and well water pretreatment system
consisting of a degassing tower, biofilter, blowers, pumps, and water storage reservoirs
cost approximately $22,000. Capital costs are summarized in Table 1.
Table 1: Summary of capital requirements for a hypothetical 12-greenhouse facility.
Category Year 1 Year 2 Year 3 Years 4-10
Agricultural Land $25,000 $ 0 $ 0 $ 0
Buildings & Improvements $92,880 $84,380 $84,380 $60,000
Tanks & Filtration Equipment $50,300 $46,800 $38,300 $21,600
Machinery & Equipment $51,496 $28,846 $26,263 $127,520
Office & Office Equipment $4,850 $ 0 $ 0 $3,350
Total Investment $224,526 $160,026 $148,943 $212,470
Production and Marketing Assumptions
The values used for key production parameters defining the performance of the system
were based upon averages from the five three-phase production trials carried out in HBOI
in 1999. Table 2 summarizes the key production assumptions.
Seed, feed, energy, and labor accounted for about 75% of the operating costs. Seed costs
accounted for 18% of the total operating cost. The model assumed specific pathogen free
(SPF) postlarvae were purchased at a price of $10/1000 PLs. Postlarvae were held in a
quarantine/acclimation facility for one week, during which time they were acclimated to
freshwater at a cost of $2.61/1000 PLs, assuming a survival of 85% in the acclimation
system. Feed costs represented about 20% of all operating costs. A 35% protein grower
pellet costs $0.30/lb delivered when purchased by the truckload. Labor and energy costs
each accounted for about 19% of total operating costs.
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