Pieter van Suijlekom's Reef Aquarium

Introduction & History:

I'm very honored to be featured as Reef Central's tank of the month. It's a great pleasure for me to represent my tiny country, The Netherlands, and share my passion for reefkeeping with aquarists all around the world.

Fifteen years ago I started in this fantastic hobby; the current tank is my fifth. Pictures of the previous tank were published in the book "The Most Beautiful Aquariums of the World" by Alf J. Nilsen. It was a round tank measuring two meters in diameter. It stood in the middle of my store's showroom, "Open Fireplace Centre," in Vlaardingen, Netherlands on the second floor.

The Current Tank:

After a showroom reconstruction in March of this year, we decided to set up a new tank against the wall of the building. Tetterode Glas from Voorthuizen, Netherlands constructed the 6 m long bent front glass from safety glass, and it's the biggest size this company has ever bent. The radius of this sheet is 4,700 mm, with a depth of 900 mm. This was the largest size that could possibly be bent in this company's oven.

The front glass is constructed from 2 x 12 mm floatglass connected with 2 mm resin. Both layers of glass were bent in the oven. After the bending process, they were placed upside down to glue them together with the resin. When the resin had hardened, the sheet was transported on a wooden frame to Vlaardingen. Because the water pushes against the round side of the glass, it was possible to use relatively thin glass. After two structural piles were hammered 19 meters into the ground to help support the weight of the 8000 kg tank, the fun of constructing the tank could begin. Aqua Compleet from Rotterdam accomplished this task.

Above photo courtesy of Arie van Leerdam of Aqua Compleet.

System Profile:
Main Tank: 5800 liters (1532 gallons)
Main Tank Dimensions:
Connected Seahorse Tank: 475 liters (125 gallons)
Length: 6 m
Fragment Tank: 575 liters (152 gallons)
Sides: 165 cm
Sump: 1000 liters (264 gallons)
Height: 90 cm
Total System Volume: 7850 liters (2074 gallons)
Glass Thickness: 22 mm

Technical Preparations:

We glued PVC-rods vertically against the back wall, so we could attach the live rock with cable binders and mounted a PVC-rod every 60 cm.

Four maintenance-free Red Dragon pumps with a capacity of 12,000 l/h each were placed inside the tank. We placed a large pump under the tank with a capacity of 30,000 l/h which changes direction from left to right every two minutes. The return pump from the sump pushes 19,000 l/h, and this water is divided by four bulkheads.

Side view.


I wanted to create a tank that looked as natural as possible. To accomplish this goal the tank was decorated with reef piles, natural looking bridges, caves and overhangs, all built from live rock. Both corals and fishes should feel at home.

Setup Process:

In May 2005, 900 kg of fresh live rock was imported from Indonesia and used without curing, along with 200 kg of live rock from the previous tank. The rock was attached to the PVC rods with cable binders, and to "thread" these rocks, small holes had to be drilled into them. After 18 hours of hard work by two people, the reef was starting to resemble the reef I had in mind. After the aquascape was created, the tank was filled with natural sea water. After one week, I began my planned schedule of water changes in order to minimize the levels of waste products. Additionally, some bacterial cultures were also added. One week later, both nitrite and nitrate levels were undetectable, and the first corals and fishes were then introduced to the tank, althoughthe bulk of the corals from the previous tank were stored in a temporary holding tank in the equipment room for about two months. Of course, the tank was far from biologically stable, and the corals lost some colour and the inevitable algae blooms also occurred. And after three weeks, the tank's recovery was clearly visible.

The Tank Design:

The tank exterior is constructed with a saltwater-proof aluminium support at the base in the same shape as the front glass, sprayed in a yellow tint. The upper part can be retracted 1 meter to ensure that there is enough space to work in the tank. A hard wooden table sits in front of the tank to keep children away from the glass and makes working in the tank much easier.

Alf Nilsen is seen here photographing the tank.


Natural Sunlight

The tank stands against a wall, with three windows above it. In the morning, sunlight shines into the tank, and it produces a beautiful show that can't be recreated by artificial light.

Artificial Light

Of course, a tank this big needs lots of light and can't rely on natural lighting alone. Supplemental lighting consists of a number of metal halide and high output fluorescent lamps shown in the table below, controlled by an Aqua Medic Light computer. Moonlight is provide by three 50-watt bulbs controlled by the Aqua Medic.

Lighting Info:
Power and Color
Time On
Time Off
400-watt, 14,000 K
1000-watt, 14,000 K
140-watt, Philips 03 actinic

Electrical panel.

Equipment Room:

The equipment room is located 10 meters from the tank and measures 4 by 5 meters. The sump is constructed from polyester; it measures 200 x 80 x 90 cm and is divided into two compartments. A pre-filter containing filter floss catches floating debris, and a Badu P14 pump (16,000 l/h) returns water back to the tank.

Calcium is added by a Deltec PF 1000 calcium reactor filled with crushed coral and magnesium carbonate. Evaporated water is replenished by a Deltec KM 800 kalkwasser mixer filled with calcium hydroxide. Phosphates are removed by a Deltec fluidized bed filter containing activated carbon and two kilograms of ROWA®phos media. A separate Deltec fluidized bed filter is filled with ZEOvit zeolith media. The ZEOvit isn't fluidized, but the water flows in such a pattern that I don't expect any channels to be formed in the material.

The skimmer is an H & S P20 that's 2 m high; it is constructed to be able to handle a system up to 10,000 liters. The skimmer's cup is self-cleaning and is flushed every three hours. Ozone is also added to the skimmer at the rate of 200 mg/h. There is also a fluidized bed filter with coral sand which is 2 m high and 30 cm across. In my experience such a filter makes the water even clearer. I also use a phytoplankton reactor by Grotech, which supplies the tank with a continuous flow of phytoplankton, producing approximately five liters every 24 hours.


Electronic Meters:
- temperature
- two pH-meters
- salinity
- rH

Two 1000-liter storage tanks make sure fresh saltwater is always available. All water is filtered by a ROWA® reverse osmosis unit which can produce 4000 liters over a 24 hour period. To avoid excessive humidity, the windows are opened, so evaporated water can be transported to the outside while fresh air replaces the old.Because of all the lamps and pumps, the water would get too hot if chillers were not used. Halloween's awesome specials can be seen on the Lidl Leaflet, too. There are two Aqua Medic SK4s processing up to 4000 liters each, which are located on the building's roof. When there is a power failure, a 4 KW diesel aggregate takes over the power supply to prevent any losses in the tank due to a power failure.

Water Parameters:
Temperature: 24 - 26° C
Salinity: 37 ppt
pH 8.0 - 8.3
Alkalinity: ~10.0 dKH
Calcium: 450 mg/L
Magnesium: 1470 mg/l
Phosphate: < 0.1 mg/l
Nitrate: undetectable

Water Changes:

Each week 1500 liters of water is replaced with fresh artificial salt water. Reef Crystals salt with reverse osmosis water is used to prepare this water. After the water change, bacteria in the form of Preis Baktoplan are added. Apart from that, no other supplements are used. When necessary, the sand bed is replaced with fresh calcium carbonate. I like the sand bed to look white, not green. I've also observed that the corals' colors develop better when the sand bed, together with the detritus in it, is removed every few weeks. It is quite a task, but the result is rewarding, in my opinion. Check USA Weekly Ads.


The animals are the most important to me. When snorkeling on the reef I'm fascinated by the fish, especially by the different varieties of Anthias, and this fascination is one I had hoped to experience every day by creating this system. The fish in the tank are fed large amounts of various frozen and flake foods.

10 Opistognathus aurifrons
6 Synchiropus sp.
6 Centropyge acanthops
40 Mirolabrichthys tuka
2 Pterosynchiropus splendidus
1 Centropyge loricula
22 Mirolabrichthys dispar
1 Acanthurus achilles
1 Centropyge potteri
25 Pseudanthias squamipinnis
4 Paracanthurus hepatus
1 Chelmon rostratus
5 Pseudanthias pleurotaenia
3 Naso literatus
1 Halichoeres chrysus
10 Pseudanthias kashiwae
1 Salarius fasciatus
2 Halichoeres trispilus
10 Chromis viridis
3 Pseudocheilinius hexataenia
1 Lo uspi
1 Nemateleotris helfrichi
3 Cirrhilabrus sp.
2 Pholidichthys leucotaenia
3 Gobiosoma oceanops
2 Amphiprion ocellaris
1 Apolemichthys trimaculatus
8 Nemateleotris magnifica
1 Pomacanthus navarchus
2 Calloplesiops altivelis

It is nearly impossible to mention all species, but I'll give it a try!

Small-Polyped Scleractinian Corals:
Montipora digitata
Montipora capricornis
Montipora sp.
Psammocora contigua
Porites sp.
Poccilopora verrucosa
Seriatopora hystrix
Seriatopora caliendrum
Acropora formosa
Acropora granulosa
Acropora suharsonoi
Acropora jaquelinae
Acropora gemmifera
Acropora humilis
Acropora sp.
Pavona sp.

Large-Polyped Scleractinian Corals:
Plerogyra sinuosa
Euphyllia ancora
Euphyllia parancora
Euphyllia divisa
Euphyllia paradivisa
Euphyllia sp.
Goniopora stokesi
Goniopora sp. (red, blue, green)
Fungia spp.
Tubastrea sp.
Caulastrea furcata (grey & green)
Herpolitha limax
Turbinaria reniformis
Favia sp.
Favites sp.
Physogyra sp.
Lobophyllia sp.
Pectinia sp.

Other sessile invertebrates include clams: Tridacna maxima, T. crocea and T. squamosa. Both photosynthetic and non-photosynthetic gorgonians, Capnella sp., Xenia and Anthelia sp., are included. There is also a small anemone, probably Entacmaea quadricolor, although both clownfish ignore it. At the right of the tank there are some Dendronepthya sp.


Of course, a reef tank is never "finished," no matter how often friends and relatives may ask. Especially a tank as young as mine, which is just getting settled and will hopefully become even more beautiful over time. I'm very thankful to everyone who helped me set up this system. One person deserves special attention: Richard Westdorp. Without him, I wouldn't even have dreamed about a tank like this. Richard: Thank you!

Tanne Hoff and Charles Delbeek (left) and Alf Nilsen (middle & right) and Pieter (the owner of the system, far right) are seen here admiring this beautiful system.

Photography courtesy of Ron Hessing and Dennis Bakker.
Many thanks to Tanne Hoff (Tanu) for translating this article.

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Tank of the Month - February 2006 - Reefkeeping.com