Daniel Gan's (danano) Reef Aquarium

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How It All Began:

I have always been fascinated by captive aquatic life. For over 30 years, there has always been aquatic life sharing my living space. Perhaps it was all inspired by the small Koi pond at my parents' house that I used to look after during my childhood. It was only after graduating from UT Austin in 1991 and moving to Boston that I discovered the world of marine fish and reefkeeping. I started out with a 29-gallon acrylic tank and shortly thereafter, I setup a 10-gallon nano tank as well. In the early days, I kept mainly fish, mushrooms, some hardy leather corals and zoanthids. After moving to Southern California and back to Texas with my two tanks, and then half-way around the globe with my 10-gallon, I finally rooted myself here in Singapore. It wasn't long before the upgrading process began. The 10-gallon tank soon grew into a 30-gallon and today, a 110-gallon occupies a corner in the living room.

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The 110-gallon Tank:

The seeds for my 110-gallon were planted in May 2004 and by July, all the corals and live rock from the smaller tanks were transferred to this tank. I created a semi-deep sand bed, sloping from 4" at the rear to about 2 - 3" in front. Biological filtration is provided by 130 lbs. of premium cured live rock. T5 lighting with quality mirror finish reflectors provide edge-to-edge illumination for the light loving corals and clams. A Barr Aquatics SK1600 Beckett-injected skimmer, carbon and Rowaphos keep the water crystal clear. Besides a few clams and LPS coral in the lower third of the tank, the reef slopes in the tank depict dense SPS gardens.

I also keep several pygmy angels that get along well and, so far, have been good reef citizens.

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Aquarium Profile:

There were two primary considerations when designing the tank. First, I wanted to be able to see the true colors of the reef through the glass. I decided, therefore, on starphire glass for the front and right viewing panels. The second consideration was to maximize the useable space in the tank, and this meant the overflow box would have to be external.

With ambient temperatures seldom dropping below 76º F and reaching as high as 86º F on hot afternoons, heat is an issue. Fortunately, advances in high output T5 technology have provided a viable alternative to metal halide lighting with less heat generated. Using T5 bulbs allowed me to design a much sleeker hood standing a mere 6" high. The cabinet has louvered doors and is without any side or rear panel for maximum ventilation. The dark walnut finish blends in well with the rest of the living room furniture.

Aquarium Profile:

Custom 110-gallon tank with starphire viewing panels, black backing and external overflow box (left side)
Main display tank dimensions are: 48" L x 24" W x 22" H (overflow box 6" x 16" x 14")
40-gallon sump/refugium: 36" x 18" x 16"
25-gallon holding/propagation tank: 29" x 15" x 13"
Custom-built hardwood cabinet

Filtration, Circulation & Chiller:

A 40-gallon sump sits in the cabinet partially extending out to the left below the overflow box. One Eheim 1260 external pump (2,400 L/hr) draws water from the sump, passes the water through a 1/3 HP Daeil chiller (Artica OEM) before ultimately returning it to the tank. Another Eheim, a 1262 (3,400 L/hr), serves purely as a return pump. Both pumps are run externally so as not to introduce unnecessary heat into the system. A Resun MD55 drives water into the Barr Aquatics SK1600 Beckett skimmer.

I chose to go with a powerful skimmer rated for a total water volume of up to 500 gallons to allow greater flexibility as far as stocking and future system / tank upgrades.

I use about 130 lbs. of premium Fiji and Vanuatu live rock for biofiltration. Approximately 120 lbs. of fine grade 0 sand form the semi-Deep Sand Bed, starting out at 4" at the rear sloping down to 3" in front. Chemical filtration, consisting of Rowaphos and Seachem Matrix Carbon in filter bags, are placed in a high flow area in the sump and help to keep the water crystal clear.


In addition to the two Eheim returns, I run two 6000 streams with a Tunze 7094 Multicontroller. Three Maxijet 1200 powerheads assist in minimizing dead spots. The combined maximum flow rate of almost 23,400 liters per hour translates to a maximum turnover of about 56 times, keeping the SPS happy.

Redundant Chiller

In our hot climate, and given the highly delicate nature of SPS corals, heat is an obvious major concern. A chiller and/or chiller-pump failure would be disastrous. Within a few hours, a temperature rise of a more than 8º F would be highly detrimental, especially to the SPS. Compared to the time, effort and resources put into acquiring and maintaining the tank inhabitants, the cost of adding a redundant chiller would appear insignificant. Hence, it was not a difficult decision for me to add a 1/4hp Daeil chiller to give me the piece of mind. The chiller is connected to an Eheim 1250 pump that feeds the 25-gallon propagation/holding tank which returns to the sump. As an added precaution, I also have a Fox Controller that I plan to install that will automatically switch the lights off in the event the temperature goes above 84º F.

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As I embarked on creating the reefscape, my aim was to simulate a densely packed hard coral (mainly SPS) garden and at the same time, provide a 'natural' environment for the fish to hide and swim in containing numerous crevices and caverns.

Large staghorn type live rock and a few large pieces of live rock form the base of the main reef structure, allowing pillars and spacious caverns to be created beneath the reef slopes, while also providing a refuge for the fish and other reef dwellers. I also used medium-size and flattish live rock to allow greater reefscaping options. Parts of the reef structure consist of Porites rocks that were the foundation for my earlier two tanks. Porites encrust fairly quickly and they fuse together within a few months, resulting in a very stable structure.

The two Tunze streams drop into small slots I created at the top-rear within the reef structure to ensure an unobstructed view. However, being partially hidden behind the live rock, the flow is compromised somewhat, which is why I am considering adding another Tunze stream to optimize water flow in the tank.

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Calcium & Alkalinity Supplementation:

In order to keep up with the uptake of calcium, I use a DIY modular system dual chamber calcium reactor with about 30lbs. of CaribSea ARM media in the first chamber and another 10lbs. in the second chamber. I started out with a single reaction chamber, and it wasn't long before I added a second chamber in order to keep up with the calcium demands of the corals.

Holding/propagation tank & equipment.


After getting good results with T5 bulbs in my previous 30-gallon system, they were the natural choice for my current 110-gallon setup. While the 24-watt T5s did a decent job maintaining SPS color at shallower depths, I was pleasantly surprised to discover that the 54-watt versions allowed me to maintain SPS even on the sandbed.

Top view of the T5 reflectors.

I started out with six 54-watt T5s, but it wasn't long before I increased the lighting to eight 54-watt T5s with the addition of more light demanding corals. The bulb combination now consists of five ATI Aquablue Special (11,000K) and three ATI Blue Plus (Radium equivalent) for maximum intensity and yet still provides a balanced spectrum for coral growth and color.

After using T5 bulbs for over two years, and almost nine months in my current tank, I must say that I am very pleased with the results in terms of coral growth and color. Aside from quality T5 tubes, equally important are the mirror finish ATI parabolic reflectors that rest directly on the tubes for maximum reflectivity. One of the keys to getting good results with T5 bulbs, I believe, is to keep your SPS no more than 18" from the light source. For intensely colored SPS (i.e. reds, blues, pinks, neon yellows), I keep them less than 10" away. The T5 bulbs are no more than three inches from the water surface. Three 24-watt T5 bulbs light up the refugium and another six 24-watt T5 bulbs cover the propagation tank.


The main tank is on an 11 hour photoperiod, from 12:30pm to 11:30pm. The sump-refugium is on a 10 hour partial reverse photoperiod, from 3:30am to 1:30pm. The propagation tank is also on a 10 hour partial reverse photoperiod from 7:30am to 5:30pm. This helps to maintain the pH above 8.00 after the main tank lights go out.

Maintenance & Husbandry:

I perform a 5-10 percent water change weekly using Tropic Marin salt mixed with oxygenated distilled water. Detritus build-up is siphoned once a month. The skimmer collection cup is cleaned bi-weekly. In addition, the tank viewing panels are cleaned every three days using a pair of algae-cleaning magnets. I trim the macroalgae in the refugium once a month. Bi-weekly water tests are conducted with Salifert Ca and dKH test kits. With the tank now mature and stable, other tests are performed on rare occasions. Nitrate, nitrite and phosphate levels are undetectable. As a result of exclusively using distilled water, the alkalinity tends to be lower. Therefore, I occasionally mix Reef Builder with top-off water to raise the dKH when needed. I feel that frequent water changes are essential as a means for nutrient export and trace element replenishment to maintain a healthy captive reef environment.

Water Parameters:
Calcium: ~ 400 ppm
Alkalinity: 7 - 8 dKH
Specific Gravity: ~ 1.025
pH: 8.1 -8.3
Temperature: 80.4 - 81.8º
Nitrate: undetectable
Nitrite: undetectable
Phosphate: undetectable

SPS pruning is also a routine maintenance exercise but many times, I let nature take its course with the stronger species prevailing. More often than not, the chemical warfare ends in a tie or they just grow away from each other or stop growing altogether at the point of contact.


The reefscape was constructed with predominately SPS and a few fish in mind. That said, over 80 species of SPS corals now blanket the reef slopes and walls with assorted Montipora capricornis occupying the lower half. The multiple swim-through caverns provide a safe haven for the fish with ample quality live rock for their grazing.

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With a densely packed SPS dominated tank, chemical warfare is expected. I simply let the corals fight it out, although I do prune certain fast growing corals on occasion.

  • SPS: over 80 species, including various Acropora, Montipora, Millepora, Seriatopora, Stylophora, Pocillopora and Porites.

  • LPS: assorted Blastomussa, Acanthastrea, Echinophyllia, yellow Turbinaria, red-green Lobophyllia.

  • Clams: Tridacna maxima, T. crocea.

  • Fish: Flame angel, Potter's angel, Multicolor angel, Cherub angel, Purple tang, Yellow-eye Kole tang, 3 Orchid dottybacks, Mandarin goby, yellow Canary wrasse, green Leopard wrasse, black Leopard wrasse, Yellow-fin wrasse, Possum wrasse, 2 Green chromis, orange Skunk clown.

  • Invertebrates: 2 Sally lightfoot crabs, 2 Cleaner shrimp, Coco worm, Nassarius snails, Bumble bee snails, Acropora crabs.

I find that certain fish continuously pick on the live rock and bases or undersides of corals. This includes pygmy angels, tangs, some wrasses and dottybacks. The right mix and number of fish in a reef tank has its benefits. I think they help maintain an eco-balanced system by not allowing parasites to take hold in a captive environment by keeping them in check and preventing them from infesting corals. These fishes peck on anything that moves on the rocks and I think this reduces the parasite's potential to reproduce. Similarly, I believe Acropora crabs play an equally important function as guardians of their SPS homes.

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Growth sequences.

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Like many, I was initially weary of adding a pygmy angel into my tank, let alone four of them. After much research and reading on the experiences of others, I successfully kept a Cherub in my old 30-gallon, which I later transferred to the current tank. Angels add a lot of life and color to a reef tank and naturally, I took the leap of faith, gradually adding three more pygmies! I added a medium-sized Potter's and a Multicolor at the same time. A few weeks later, a small Flame angel joined the threesome. The tiny Cherub was overtly territorial and chased the larger fish initially, giving up after only a day or two. The angels stay fat from simply grazing the live rock, and they all take Formula 1 & 2 except for the Potter's. They take an occasional rare nip at an SPS polyp or two, nothing more.

The Orchid dottybacks, Cleaner shrimp, Sally lightfoot and acro crabs have all spawned in the tank. In every instance that I've witnessed, it occurred about an hour after lights out.

Feeding and Supplements:

I feed the fish Formula 1 & 2 pellets every two to three days. For general consumption, I feed a stew of Liquid Life Bioplankton, finely chopped nori, Cyclop-Eeze® and Formula 1 flake once a week.

The angels, tangs, mandarins and wrasses are self-sustaining. They graze and peck on the live rock the whole day. The orchids, clown, chromis and yellow fin wrasse require supplemental feeding.

I dose iodine and amino acids for potential benefits to the corals. I have noticed what I believe to be slightly improved coloration and polyp extension with the addition of amino acids.


About a week ago, I made an amazing discovery! What I found was a natural offspring of one of the SPS corals in my tank. I noticed a small growth, encrusting on the top edge of the overflow glass leading to the last compartment in the sump. The encrusting growth is about the size of a small coin with tiny bumps/branches/polyps beginning to form. On closer inspection, the mother colony is likely the purple or pink Pocillopora sp. in the main tank. There are two other smaller encrusting spots along the same glass edge. T5 bulbs light up the sump/refugium on a reverse photoperiod, providing indirect light to the last compartment and it's apparently enough light for the new SPS growth. Needless to say, I was very excited about the new find, and I am still amazed! I estimate that the baby colonies are probably no more than six to eight weeks old.


I would not have made it this far without the support and understanding from my loving wife. In fact, on one occasion, she picked out, with her trained and discerning eye, the purple A. humilis that now sits smack at the highest point of the tank. Together, we enjoy our small piece of the ocean in the living room and never seem to get bored staring into it, always amazed and discovering something new each time!

It's a special joy to see the corals grow and color up. And it's an equal joy to see the fish swimming among the corals and crevices and greet us when we are near. And it's the continuous challenge plus learning and sharing of experiences that makes this hobby and passion of ours so enjoyable and addictive!

Most of all, a special appreciation goes out to Reef Central and a big, "Thank you!" to Reefkeeping Magazine for the excellent articles and tank features, which have been an invaluable source of information and inspiration for me! I would like to add that I am truly honored to be given this opportunity to share with you our small piece of the ocean!

Macro shots:
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**All photos copyright Daniel Gan.**

Feel free to comment or ask questions about my tank in the Tank of the Month thread on Reef Central.

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Tank of the Month - March 2005 - Reefkeeping.com