The Berlin Method
In the 1970s, as reefkeeping was evolving in Europe, Peter
Wilkens of the Berlin Marine Association came up with the Berlin
method. This way of running a reef aquarium worked very well,
and it spread due to its success. In fact, by the 1980s it had made
its way to the U.S., and it was basically the way that a reef aquarium
was set up and operated.
Bright lights were needed, as well as a lot of live rock and a
gravel or sand substrate. High water flow was also a must, along
with regular partial water changes and the use of kalkwasser,
activated carbon, and trace element supplements. A skimmer was
another requirement, typically being placed in a flow-through sump
plumbed under the aquarium. Heaters, bags of carbon, and other
elements could also be placed in the sump and out of sight.
Some other things were going on, too. Wet-dry filters, also
known as trickle filters, were developed in Europe, and these were
also being used as under-tank biological filters on marine and reef
aquariums in the 1970s. In the case of reef aquariums, these filters
were superior to undergravel filters, since much of one would be
covered by live rock in a reef tank, making it less effective and also
essentially impossible to clean. A wet-dry also served as a sump.
It took about 10 years, but these also caught on in the U.S., and
I had one on my first reef aquarium in 1992. However, by the late
1980s, word was getting out here that they weren’t needed on a reef
aquarium, as long as plenty of live rock was being used. The rock
itself worked just fine as a biological filter. It was the publication
of The Reef Aquarium Vol. 1 by Charles Delbeek and Julian Sprung
(Ricordea Publishing, 1994) that convinced me to remove it, and
as best as I know, everyone that was still using a wet-dry on a reef
aquarium stopped doing so around that time.
There was also some back-and-forth on the use of substrates.
Initially, a bed of coarse gravel was typically used in a Berlin-method aquarium, but this could get clogged with nutrient-rich
detritus over time. So many hobbyists started running their
aquariums with no substrate—bare-bottomed, as they called it.
With sufficient water motion, particulate matter would stay in
suspension and could be removed with a mechanical filter or
filter floss employed in a wet-dry/sump, rather than settling to the
bottom and accumulating in the substrate.
I’ll also point out that magazine articles about reefkeeping had
become commonplace by the 1980s, and numerous books were
hitting the shelves in the late ’80s and early ’90s. This was obviously
long before the Internet was in place, and quite a few good books on
livestock and reef aquarium methodology were must-haves. Folks
were really getting this whole reef aquarium thing figured out, and
they were spreading the word.
Tropical Fish Hobbyist www.tfhmagazine.com 57
The use of metal halide lighting along with actinic fluorescent bulbs was a game-changer, as it meant that all sorts of photosynthetic reef organisms
could be maintained in captivity without relying on natural sunlight to keep them alive.
Macroalgae of various sorts, such as this Caulerpa, have
been broadly used as a type of biological filtration in marine
aquariums since being popularized by Lee Chin Eng in the