Owner: Sanjay Joshi
Location: Pennsylvania
Web page: http://www.personal.psu.edu/sbj4/aquarium/aquarium.html

Full view of the owner enjoying his 180-gallon reef tank.


The tank is a standard 180 gallon (6 x 2 x 2 feet) manufactured by All Glass Aquarium. I had the tank modified by having two slots — 1 inch wide x 10 inches long — cut into the back of the tank. These slots were were created using sand blasting because they are difficult to cut otherwise. Attached to the tank, on the inside, is a box (2 inches wide x 2 inches high x 36 inches long) that serves as a surface skimmer. On the outside of the tank is a box (36 inches long x 8 inches wide x 10 inches high) that serves as a mini sump and provides a location for the heaters and powerheads outside of the tank. This hang-on-the-tank sump has a 2-inch bulkhead for water return to the main sumps under the tank. A standpipe helps maintain the water level in this mini-sump. I also had two smaller ¾-inch bulkheads fitted to either side of this sump to allow for future extraction of tank water for plumbing extensions to the system (such as a grow-out tank or refugium).

Main Plumbing and Water Circulation

The sump consists of two 27-gallon Rubbermaid containers (placed lengthwise) connected via a 1½-inch bulkhead. Two additional bulkheads were added to the sump, one at each end. One of the bulkheads is connected to a Little Giant 4 MDQX pump, which is used as the main water return to the tank. The main water return is split into two — one in each front corner of the tank — and is directed from front of the tank to the back so that the currents hit the rock and corals directly. The other bulkhead is used to draw water for the skimmer via a Gen-X pump. The skimmed water is returned back to the same part of the sump to minimize air bubbles in the system.

Additional water movement is provided through the use of four powerheads. All these powerheads are placed in the outside mini-sump and are kept out of the main display area. The water return from two of the powerheads is also directed from the front to the back, and two Hagen 802 powerheads return water from the back to the front direction. A Tsunami Wavemaker controls the powerheads.

Schematic of the Tank Modifications.


The live rock in the tank consists primarily of 200 pounds of choice pieces of Florida Keys rock supplied by Exotic Aquaria, 30 pounds of branching Tonga rock and about 10 pounds of Fiji rock. The rock is arranged in a very open and loose structure, creating large open areas and caves in the rockwork to facilitate water circulation through the rock. The substrate consists of 200 pounds of Florida Keys live sand. The substrate ranges in thickness from 1 inch in the front to about 3 inches at the back.

Other Filtration

The filtration system for the tank is a 5½-foot tall, do-it-yourself downdraft skimmer powered by a Gen-X pump. A H.O.T. Magnum filter is used as a carbon filter, and is run continuously. No other mechanical or chemical form of filtration is used.

Water Preparation

The make-up water used is run through a Spectra Pure CSP-50 reverse osmosis (RO) unit. This unit provides all the make-up water and replacement water. A 20-gallon trash can is used to store the make-up water. A solenoid (sold through SpectraPure) is used to provide the automatic shut off for the RO unit when the 20-gallon storage container is full. To replace the water lost due to evaporation, a reef-filler pump is used. Depending on the time of year, about 1½ to 2 gallons of water is lost due to evaporation.

For replacement water, I use Instant Ocean salt mix. This is the only salt I have used in this tank. Replacement water is mixed with salt and stirred continuously with a powerhead over one to two days. A heater is used to bring the temperature up to the tank water temperature.


Current lighting consists of two 400-watt, 6500 Kelvin (K) Iwasaki metal halide lamps, one 20,000 K Osram, and one 250-watt Iwaski 6500 K metal halide lamp. The two 400-watt lamps were just recently switched from 250 watts in December 1997. In the near future, the remaining 250-watt lamp will be replaced by a 400-watt lamp.

In addition, four 40-watt normal output actinc 03 fluorescent lamps are also used to provide additional blue light. The actinic lights are on for a photoperiod of 12 hours and the metal halide lights are on for 10 hours. The metal halide lights turn on an hour after the actinics and turn off an hour before the actinics to simulate a dawn and dusk period.

Closeup of the beautiful stony coral garden Sanjay created in his 180-gallon reef tank.


Calcium and alkalinity are maintained in the tank using a calcium carbonate reactor. The reactor has been in use now for a year and a half. The reactor effluent is the only additive I currently add to the system. Since about a year ago, no other additives have been added.

Water Parameters

Temperature Range = 79 to 82 degrees Fahrenheit in winter and 81 to 84 degrees in summer
Salinity = 1.022 specific gravity
Alkalinity = 8 to 10 dkH
Calcium = 380 to 420 parts per million
Nitrates and phosphates were undetectable with the LaMotte test kit when I last checked over a year ago. It has not been checked since then.

Basic Maintenance

I am the consummate lazy aquarist and avoid any maintenance other than what is absolutely necessary. My basic maintenance routine consists of glancing at the temperature, water levels, drip from the reactor and pH to ensure that everthing is operational. I do this typically when feeding the tank. The tank is well fed — I feed the tank daily, with my own food mix.

In addition, I clean the front glass of the aquarium every four to five days. I leave my cleaning magnets in the tank, so cleaning the front glass is really not a chore anymore. The skimmer needs to be cleaned bi-weekly, and I replace half the carbon in the cannister every month. A 20-gallon water change is made every three to four months, or when I remember. Water testing is performed once every month or so, and consists primarily of checking the calcium and alkalinity values. Actually, I can get a pretty good idea if the values of alkalinty and calcium are not up to par by observing the growth rate on some of the fast-growing corals.

So basically, it’s is a very low maintenance tank. I’d rather spend my time looking at the tank than maintaining it. And believe me, it can be done!

Another closeup of the beautiful stony coral garden.

Tank Inhabitants


I am not good at identifying the various Acroporaspecies, so take what follows as my best guess.
Six medium to large colonies of various unidentified Acropora sp., three A. formosa, two large colonies of blue tipped table top Acropora, A. palifera, A. humilis, A. gemmifera, A. microphthalma, A. cerealis, A. yongei, A. abrolhensis, A. millipora and several small colonies of Acropora grown from fragments. Pocillopora damicornis from several colonies that have grown from a planula from a large mother colony: P. damicornis green morph and three pink P. verrucosa. Two pink Stylophora pistillata, two Montipora digitata, two pink/orange M. digitata, two green M. digitata, M. confusa, orange M. capricornis, green M. capricornis, Hydnophora excessa, two pink Seriatopora hystrix, gold S. hystrix, S. caliendrum, three yellow Porites cylindrica, three encrusting blue/green Porites, Turbinaria reniformis, Oulophyllia, Merulina ampliata, Pectinia paeonia, Pavona cactus, Pavona decussata, Blastomussa wellsi, Oxypora glabra, Mycedium elephantotus, Favia, Leptoseris mycetoseroides, Echinata lameolosa and Fungia.


Yellow tang (Zebrasoma flavescens), purple tang (Zebrasoma xanthurum), Red Sea sailfin tang (Zebrasoma desjardinii), lime green wrasse (Halichoeres chloropterus), two Pseudanthias squamipinnis, Pseudochromis springerii, green chromis (Chromis caeruleus), yellow tail blue damsel (Chrysiptera parasema), Swissguard basslet (Liopropoma rubre), Banggaie cardinalfish (Pterapogon kauderni) and a flame angel (Centropyge loriculus).


Tridacna gigas, one large and three small T. maxima and T. derasa.

Other Inhabitants

Sixteen serpent stars (Ophioderma sp.), one red serpent star (Ophioderma rubricundrum), three sea cucumbers (Holothuria floridiana), sea biscuit (Clypeaster subdepressus), coral banded shrimp (Stenopus hispidus), several brittle stars, two pistol shrimp (Alpheus armatus), 20 Astraea sp. snails and a few herbivorous hermit crabs (Clibinarius tricolor) (left over from the 200 added when the tank was started).

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