plywood. The 30 cm high sidewall and center divider of
the raceway were also covered in 2 cm plywood except
at the curved ends. The 1.2 m (radius) curved ends of the
raceway were built out of 3 layers of 0.6 cm plywood.
This thin and flexible plywood formed the 1.2 m radius
curve without breaking. The drain was countersunk
2 cm to aid periodic draining of the raceway, and the
drain hole was fitted with a 10 cm diameter, schedule 40
bulkhead fitting. The drain was fit with a bottom-draining
standpipe to maintain a constant water level. Construction
materials are all available from local home
improvement stores and plumbing suppliers in the U.S.
(e.g. The Home Depot). Two layers of 283 g fiber-cloth and polyester resin (Kardol LLC, Lebanon, Ohio) were
used as a base layer in the raceway for waterproofing
and structural integrity.Waterproofing was finished with
2 additional layers of white Gel-Coat (Kardol LLC,
Lebanon, Ohio), which also provided ∼25% reflectance
of incident light. The raceway was then covered with 2
layers of 60% greenhouse shade-cloth (Farmtek Inc.,
Dyersville, IA) suspended 2 m above the raceway on
wood framing to reduce irradiance and solar gain.Water
temperature and other environmental conditions were
maintained with 50 L min−1 make-up flow with seawater
pumped from Taunton Bay, ME (sand filter
pretreatment) to further counter the effects of solar gain.