The second scenario is not a likely one for many hobbyists but since
this type of conversion has been performed flawlessly enough times we
feel confident in describing the method. As in the first example the
aquarium is filled with fish and invertebrates but differs in that the
live rock may be covered with undesirable algae, perhaps with none of
its original beauty alive underneath. This procedure requires several
hours and is best done on a weekend. In addition, you will need new
seawater and seeded live rock. To use unseeded rock would be a certain
death sentence for the previous inhabitants. Shut off the water pump
but leave the filter and prefilter undisturbed; remove all fish and
invertebrates to buckets of tank water and aerate, be sure to place
the fish in separate buckets or aquaria, from the inverts; remove all
the rock and check to see if there are any pieces that may be reused.
The following is done to the aquarium: remove all detritus and algae;
fill the aquarium with new seawater and add new seeded live rock which
has been held in an established aquarium for at least three weeks,
rocks with obvious signs of fouling i.e. white sloughing film, black,
sulfur-smelling areas should be avoided. While adding the rock one
must keep an eye on the sump and remove excess water as required. The
pump should be restarted after ensuring that the rock has been
arranged aesthetically and allows adequate water circulation. At this
time the temperature will adjust to what is normal for the aquarium
and the old prefilter will begin to trap detritus from the new rock.
You can then open a few packs of Chemi-PureR and shake them IN THE
AQUARIUM before placing them in the sump. Such fine activated carbon
dust is used in organic chemistry labs to instantly remove organic
impurities from solutions. Used in the aquarium, this fine dust will
adsorb organic leachates given off by the new rock as a result of
handling. Within an hour, depending on the turnover rate of the
aquarium, the water will be crystal clear and the carbon dust, with
the adsorbed organics, will have been trapped in the prefilter. The
prefilter can then be simply thrown away and replaced with fresh
material. The protein skimmer is shut off during this period as the
carbon dust will quickly coat the skimmer tube. As long as the
temperature, salinity and pH are adjusted to match the water in which
the organisms came from, they can then be returned to the aquarium.
After at least two weeks but preferably a month or more, the trickle
filter can be removed from the system and the skimmer replumbed, if
necessary, to ensure surface extraction from the aquarium. Of course
one should constantly monitor ammonia and nitrite levels throughout
the period after the new rock has been added. The longer the rock is
allowed to become established in the aquarium before removing the
trickle filter, the better its ability will be to perform as a
nitrifying filter.

Establishing an Aquarium without a Trickle Filter
Setting up an aquarium without a trickle filter has as many methods as
there are aquarists who have tried it. Still, at least two distinct
subdivisions exist: starting with seeded live rock and starting with
foul, stinking, rotten rock. As most hobbyists obtain their rock in
the latter condition, we will consider that method first.

When live rock is first received it should be rinsed in fresh seawater
in order to remove such goodies as newspaper ink, algae leachates,
sand, muck and ammonia that have been released by the rock inhabitants
during transport. Excessive sponge and algae growth should be removed
also, if this has not already been done for you by the supplier.
CAUTION HERE! The average hobbyist is poorly able to distinguish
between sponge, coral and meatloaf. A rare, desirable specimen could
be lost to indescriminant cleaning. Experience, combined with reading
will prepare the hobbyist to judge what's good and what's not. The
algae should be removed too since the rock will be stacked in such a
way that it will be crushed or shaded anyway. The live rock may be
seeded in an aquarium separate from the main tank or simply put right
in. Most hobbyists only have facilities for the latter. The use of
carbon dust as described earlier may be used to help clear the water
of yellowing compounds released by the fresh rock. One should monitor
the level of ammonia and nitrite over the next few weeks. Typically,
the aquarium set-up with fresh rock will cycle within ten days and two
weeks. However, this is highly variable and sometimes a tank will show
very little ammonia or very high amounts. As a general rule, as long
as their are no white, filmy areas on the rock and no measurable
ammonia or nitrite, animals can begin to be introduced within two
weeks. However, it must be understood that the most successful
exhibits are created as much with patience as with skill and waiting
longer before adding specimens is highly recommended. It should also
be apparent that a completed nitrogen cycle is not an indication that
the rock is completely seeded, only that the bacteria colonies have
developed sufficiently so that the rock is no longer producing ammonia
and nitrite. Again, the longer one waits before adding any specimens,
the better. Some hobbyists may wait as long as six months before
adding any fish (A.J. Nilsen, personal communication, 1990), though it
is not essential to be so extremely patient. As a general rule, it is
safe to add fish after one month of seeding the tank. However,
delaying the introduction of fish also allows the populations of
various creatures and algae to increase and strengthen such that they
will provide a stable food source once the fish are added.

Some other specifications are in order. It is good practice to leave
the lights off during the seeding process as it is during this period
that algae nutrients will be at their highest, and high intensity
lighting can stimulate excessive algae growth. In addition, the growth
of nitrifying bacteria is inhibited by light. Stacking of the rock in
a loose arrangement, with plenty of gaps and open spaces, will
facilitate the circulation of oxygen rich water throughout the reef
structure and aid seeding; do not create a tight brick wall! If one
has to purchase live rock in small amounts due to budget restraints,
and the aquarium contains fish and valued invertebrates, then it is
essential that the rock be well-seeded before they are placed in the
aquarium. As soon as ammonia and nitrite parameters reach acceptable
levels you can add a number of herbivores to the tank. In our opinion
the marine snail Astrea tecta, is an excellent candidate and a tank
set-up by J. Sprung always contains approximately 1 snail per gallon.
These snails are introduced as soon as possible and effectively limit
the development of microalgae. Finally, your skimmer will be pulling
out excessive amounts of material during the seeding process, make
sure you empty the collection cup regularly and clean the skimmer tube
frequently to maintain peak efficiency.

Starting an aquarium without a trickle filter but with skimmers and
well-seeded live rock is the easiest technique. It is possible to
create a balanced aquarium in a day with this method, and if the fish
are quarantined in advance and properly selected, the margin of safety
is quite good. As before, while it is possible to create a balanced
environment rather quickly, it is always best to be patient and
proceed slowly. In the goal of achieving a wonderfully beautiful and
educational natural ecosystem, it would be a shame to risk killing
organisms needlessly because of a lack of patience.

In summary, we are not saying that trickle filters are no longer
necessary on marine aquariums. On the contrary, we both have seen
innumerable systems that are run very successfully with trickle
filters. However, we feel that there are alternatives to these
filtration systems that have demonstrated equal, if not superior,
results. It is also interesting to note that the systems discussed in
this article have achieved excellent results without the use of
technological aids such as ozone generators, CO2 injection systems,
oxygen reactors and pH/redox controllers.

With regards to lighting everyone knows about the ongoing debate over
metal halide versus fluorescent lamps. Both authors use fluorescent
lighting for the simple reason that it is the most suitable form of
lighting for their aquariums; your needs may differ. Others, such as
Mr. Stüber, believe that the specific metal halide lamps he and others
use, are best for the systems they are running. As always the hobbyist
must determine their own lighting requirements based on the type and
size of system they wish to run and the type of organisms they plan to
keep.

We wish to make it clear that properly planned "natural system"
aquaria are NOT more fragile or difficult to balance and maintain than
their wet/dry counterparts. Still, a full appreciation of the margins
of safety and the element of patience are qualities of the experienced
hobbyist, not the newcomer. For this reason we do not recommend that
the unseasoned hobbyist attempt these methods.

Hobbyists should be constantly striving to maintain their animals
under the best possible conditions and if one system appears to work
better than another in achieving this goal, then we should explore
them. Have you ever wondered why it took so long for the miniature
reef concept to reach North America? Let us not allow ourselves to
fall behind again. Keep an open mind and don't be afraid to
experiment. So it is with both excitement and caution that we present
these techniques, in the hope that they become accepted and respected
in North America and elsewhere.

Acknowledgments
We would like to thank Thomas A. Frakes of Aquarium Systems Inc., A.J.
Nilsen and D. Stüber for the use of their photos and extremely helpful
information, and A. Molder for providing first hand observations on
West German reef systems.

References
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Emmens, C.W. 1986. The natural system and the minireef. Freshwater and
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Eng, L.C. 1961. Nature's system of keeping marine fishes. Tropical
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Jaubert, J. 1989. An integrated nitrifying-denitrifying biological
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Jaubert, J. and J-P. Gattuso, 1989. Changements de forme provoques par
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