hen it comes to planning a reef
tank, you usually have a fairly
good idea of what you want to do.
You make your lists and sketches,
purchase your equipment, build the
system at your own pace, and then
begin the slow, methodical process of
stocking the system. You monitor water chemistry routinely, fine-tuning calcium, alkalinity,
and magnesium, keep checking your water-quality maintenance devices—GFO reactors, carbon reactors, refugiums, and so on, and then watch as your system matures
and grows in. Sounds pretty straightforward, doesn’t it?
Now imagine, instead, that you have been given a
partially built system, designed by someone else. Your
task is to finish the work, add fish to the tank, and then
open your doors to anyone who wants to have a look. On
top of everything else, you will be asking people to pay
to come and see your aquarium. It had better be great
from day one.
Imagine that you have to get all the systems up and
W
Managing the aquarium’s reef system has been an
eye-opening experience. Even simple things like boosting calcium or magnesium levels involves large quantities of chemicals that must be purchased at a reasonable
cost and added to the system very carefully. Many of the
issues we face are similar to those encountered by the
home aquarist, but they are on a much larger scale and
involve a staggering investment in livestock, and it takes
much longer for the benefits or harm resulting from our
actions to become apparent.
In preparation for the construction and operation of
this new exhibit, the Academy first built a 15-foot-deep
( 4.5-m), 20,000-gallon ( 76,000-L) reef tank at its temporary exhibit space in downtown San Francisco. This
system was used to develop proofs of concept and to test
lighting and filtration systems.
LIGHTING
As you can well imagine, lighting can a challenge in a
tank over 20 feet ( 6 m) deep. We had many concerns
about getting enough illumination to support the popu-
GRAND SCALE
running and manage the water chemistry, motion, and
lighting—all before the crowds arrive. Consider that every decision you make has to be run by various other
people who may or may not agree with you and who
control how much money you can spend to get the job
done. If you understand how challenging the planning
and setup of a new reef system can be for the average
home aquarium hobbyist, I am sure you can appreciate
the amount of work required to set up a 200,000-gallon
(757,000-L) system.
J. CHARLES DELBEEK
A MONUMENTAL TASK
This is exactly the situation I found myself in in June
of 2008, along with Richard Ross, Matt Wandell, Seth
Wolters, Bart Shepherd, and the engineering staff at the
California Academy of Science’s Steinhart Aquarium in
San Francisco. Our mandate was to present a Philippine
Coral Reef exhibit 22 feet ( 6. 7 meters) deep, holding
more than 3,000 coral reef fishes and live corals. The
goal was to educate and delight millions of visitors; most
of them would have no idea what goes on behind the
scenes to make such a huge system work.
A work in progress: the new 200,000-gallon Philippine Coral
Reef at the Steinhart Aquarium in San Franscisco.
lation of photosynthetic animals. Initially, our intent was
to use 2000-W metal halides, but after extensive testing
of various lighting systems it became apparent that our
European manufacturer could not supply a reliable, safe
option that could work in North America in time for the
installation of the lighting system over the new exhibit.
After a series of back-and-forth negotiations with the
architects, we settled on the idea of placing the lights closer to the water than we had previously thought possible.
This allowed us to use 1000-W American-made metal halide fixtures over the deepest parts of the tank. The initial
lamping of the lights occurred months before the grand
opening in September 2008, and the lamps were not
changed until April of 2009. Replacing the lamps has doubled the PAR levels in many sections of the tank. Skylights
and windows adjacent to the tank allow natural sunlight
to reach the exhibit at certain times of the year. Unfortunately, only circles of light fall on the tank through the
skylights, and as the earth rotates these circles migrate
across the tank, resulting in uneven PAR levels: corals that
had been receiving 150–200 uE/m2/s can be subjected
to over 1000 uE/m2/s when these circles of sunlight
pass overhead. Add into this equation that the corals in
the tank had been grown under steady levels of light, in
some cases for years, in the old Steinhart Aquarium before
