Tuan Pham's (tlp) Reef Aquarium

Introduction:

I am very proud and flattered to have been asked to write about my efforts for Tank of the Month on Reef Central. Relative to many reefkeepers around the world, I have very little knowledge and experience, so this opportunity to share my pride and joy with everyone is absolutely fantastic.

I started keeping a marine reef tank about four years ago. I was drawn to the hobby because it was challenging and rewarding, something that would keep my continued interest for a long time, and something that would both tax and relax. Little did I know how involving this hobby really is, and how enjoyable! Especially enjoyable is incorporating my love of photography to take macro photos of a whole new world, of which I was previously totally unaware. Here's my story.

Not being a purist, I've not attempted to adhere to any kind of biotopic principle in stocking, and have opted instead for variety in structure and colours when choosing corals. In an attempt to elicit continued visual interest in the tank, the corals were placed in a 3-D fashion so that as the viewer looks around the corners he finds more to discover behind the rocks. While aquascaping I kept the rock structures quite low, as I wanted to let the coral formations show through, so the rock structure is shaped more openly than the standard "fruit store" structure.

Colour contrasts, the corals' eventual growth patterns, and lighting/flow requirements were all taken into consideration when placing the corals, although sometimes placement actually comes down to which part of the tank I can reach without getting drowned. Short arms and legs don't work too well in deep tanks!

SPS Corals:

I have approximately 24 Acropora colonies of various colours and growth shapes. The majority have been either grown from fragments or purchased as aquacultured fragments. Having purchased and looked through Veron's hefty books, I've given up trying to accurately identify the species of most of them.

Some have terrific growth rates. This Montipora sp. (below) was given to me when the tank was first built. Two years later it has grown so large that it has broken off its base several times and I've been able to donate quite a few accidental fragments to the reefing community. In some places the corals have grown closely together and created a mesh of colours.

March 2003	November 2003	May 2004	March 2005

LPS Corals:

A section of the tank is dedicated to a few LPS corals; one or two more are scattered about here and there in areas of low flow and less intense lighting, although the water conditions are still not quite the ideal turbid environment similar to their original, natural habitat. Some of these corals were grown from fragments, such as the Euphyllia; the rest were purchased as wild colonies.

Anemones:

One day when I found a gorgeous Rose Bubble Tip anemone at the LFS, I was frustrated because it was already reserved. Months later, I heard it had split, and I had to have the clone. Twice we traveled a long way to buy it from a fellow reefkeeper: the first time it refused to be removed from a quite large piece of rock, but the second time we got lucky and I obtained it. I was lucky again as it had an unfortunate mishap and found its way into the grill of my closed loop system, where it was shredded, but I managed to nurse its remains back to full health.

Since then it has split many times; some clones have been traded, and some are still with me as they are too stubborn to leave their rocky footing. Along with another green bubble tip anemone nearby, the four remaining BTA's are the comfortable homes for a group of five A. ocellaris clownfish.

I also have another strikingly handsome anemone, a Cerianthid (above right), with bright orange tentacles and a fluorescent green center. This anemone can grow quite large and has a potent sting, although I have had no problems with it.

My Wet Friends:

I like fish; a lot of fish! I just love the absolutely fantastic vibrant colours, shapes and patterns on reef fishes that make me think Mother Nature was in a drug-induced hallucination during their creation. I suspect that many hardcore SPS reefkeepers are probably shaking their heads saying, "tut, tut," and will shudder at my stocking list, as this isn't exactly the purely "lab-like" low bioload environment for the corals.

Influenced greatly by a speaker at a seminar I attended, I've attempted to keep fish in pairs or groups whenever possible, with partial success. Often it has been difficult to find pairs, but when it works it is very rewarding; the courting display and spawning of these pairs are fantastic to watch from the comfort of my own house (even though I end up feeling like some sort of perverted peeping Tom!).

My favourite pair of all time is "Mr. & Mrs. Mandarin." I endured many early heartaches to find a mate for my first fish, but now they're the sweetest pair of fish I could find. They seem so much "in love." They literally sleep together every night, cuddled up in the same "hole" within a fin's length of one another.

Other Invertebrates:

Along with several hundred various snails, four short spined Tuxedo urchins keep the algae at bay; one very large black sea cucumber and a few tigertail cucumbers keep the sand bed clean. A few red leg hermits here and there help remove uneaten food from the rocks.

I also keep several pistol shrimps, most of which I hardly ever see, but their presence is confirmed by clicking noises during the night. They help agitate the deep sand bed a little as they burrow deep and wide throughout the tank.

Design:

Foremost in my mind at the time of designing the system was the maintenance side of reefkeeping. I know that if something is hard to do, I will not have the patience to do it, so if the tank was going to be a long-term success, it would have to be low maintenance. In my opinion, many projects fail because a lack of consideration is given to long-term maintenance, and after the initial honeymoon period when the adrenaline of a new tank has ebbed a bit, people simply give up. So I aimed for a system that I imagined myself working with four or five years down the line when life circumstances might make it very hard to spend time on the tank.

System Profile:

Main Display: 7' x 4' x 2.5' 150kg of live rock, 5-6" sand bed, four 400-watt metal halides, four 54-watt T5 bulbs, two 80-watt T5 actinic bulbs. Refugium: 8' x 2' Twin 150-watt metal halides on a reverse daylight cycle. Fragment Grow-out Tank: 5' x 2'. Lit by six 54-watt T5 bulbs. Main Sump: 5' x 3' Water Change Sump: 8' x 2'

Large Refugium:

My idea was to try to build an ecosystem that could survive for weeks without attention. Central to this goal is a large (8' x 2') refugium that feeds the tank a constant supply of live food. A vast area of deep sand bed, live rocks and macroalgae, combined with a lack of predation, make the strongly lit refugium the lifeline of the tank. And, of course, it had to be above the main tank so that all the lovely pods and planktonic food wouldn't be destroyed by the pumps.

Display Tank:

Using the garage as my fish room, I wanted to create as much depth as possible, yet keep the tank shallow enough that, even with my short arms and legs, I could reach in. The desired depth of the tank added to its volume and necessitated using thicker glass, so I selected Starphire for the front display panel for its increased clarity.

The tank's viewing area is cut into the wall of the room to hide 6" of space on each side of the tank so that the plumbing can run down the corners and out of sight. The tank's bottom 6" is also hidden, as I didn't want to look directly at the deep sand bed all the time. The sand bed also hides a few pipes leading to nozzles in the rock structures that keep the live rocks well-flushed by the closed-loop pumps.

I also added the fragment grow-out tank to the wish list, as I had experimented with a few propagation ventures and sold /exchanged about $900 worth of corals during my first tank's era. This grow-out tank is 5' x 2' and only 18" high, to allow the use of T5 fluorescent tubes for lighting. Old Maxijet powerheads and the odd Eheim pump here and there provide plenty of flow in this tank. Additionally, some of the rich(er) water from the refugium flows into this tank to feed the corals.

Sump and Water Changes:

Again with maintenance in mind, I thought about how to do a water change on such a large scale as this tank would require, as my previous method using buckets was clearly inadequate. The simple low-tech answer was to use two sumps: a large 5' x 3' sump under the display tank is the core vessel, and a second 8' x 2' tank, which is taller, is used only for water changes.

The overflow from the display tank is divided; some falls into the water change vessel and some loops up into the air so the pipe is higher than the first outlet (see diagram below), eventually falling back down into the main sump. During normal use, the majority of the tank's overflow falls into the water change sump as the path of least resistance. The water change vessel has an overflow at its opposite end that returns the water back to the main sump.

To carry out a water change, I stop the water overflowing into the water change sump using a gate valve, so that all of the display tank's overflow goes directly into the main sump. The dirty water is pumped out of the water change sump, a quick run of the wet/dry vacuum clears the bottom of detritus and other rubbish, and then RO/DI water fills it (a mechanical float valve shuts off the RO at the desired level). I add about a bucket and a half of salt and mix it well with a large submersible pump, then leave it for 24-48 hours to aerate and rise to the main display's temperature. A quick test confirms the salinity, and then the isolating gate valve is turned on again which adds the tank's overflow into this vessel and gradually mixes in the new water. About 18% of the system's total volume can be changed this way.

An additional benefit is that this sump can hold the entire tank's livestock if disaster strikes, or it can be used as a livestock isolation/quarantine tank with very little effort. All I have to do is turn the valve off, move the lighting rig from the fragment grow out tank to this one and I'm in business.

Adding all of the tanks and sumps together yields a total water volume of over 11,000 gallons (US), thus providing a very stable system.

Circulation:

A pair of 1/6HP Sequence pumps, one on each side, provide circulation within the main tank, with outlets hidden among the rocks and in each of the tank's corners. These closed-loop pumps operate constantly at maximum power and are powerful enough to generate vortices in the water column when the tank was devoid of livestock. Many ball valves were used to fine-tune the flow to each of the outlets.

As time passed and the corals grew more densely, three pairs of Tunze 6100 stream pumps were added, powered by a Tunze 7094 wave controller, bringing the total circulation up to a more respectable level of 50x the tank's volume. I didn't want to add all the pumps right at the beginning as I find that in strong flow the SPS colonies grow in tight formation, so if they're subjected to very strong flow at the start it gets harder and harder to increase the flow later, as they grow.

Live Rock Filtration:

Water Parameters: Temperature: 25ºC - Winter, 27-29ºC - Summer Specific Gravity: ~ 1.026 pH: 8.3 - 8.5 Calcium: ~ 380-420ppm Alkalinity: ~7.5-8.0 dKH Magnesium: 1280-1300 PO4: low NO3: low

Like many, I strongly believe that good in-tank circulation is absolutely vital to a healthy reef and, even more importantly, an open living rock structure can produce better filtration than using a lot more rocks that are poorly arranged. In total, about 130kg of live rock was used in the tank. I was lucky enough to be able to hand pick the pieces, and I chose large but irregular pieces that would allow me to build a two-level structure. This design requires fewer rocks, yet still allows for an "open" structure, both to facilitate flow and to give the fishes plenty of room to swim. Instead of building the rocks up into a wall at the rear of the tank as per the traditional look, I opted to keep the whole structure fairly low and tried to choose fast-growing branching corals to grow at the rear.

I cured the live rock myself using the live phytoplankton method with a lot of live sand. Apparently, the live rocks were flown in, picked up at the airport and then delivered to me immediately, so they had been in transit for only 48 hours in insulated boxes. Their freshness, combined with my effort to cure them in the tank with lighting, meant that most of the life on the rocks was preserved with very little die-off in the initial stage. I even have some colonies of corals that were hitchhiking freebies, including a rather nice purple Acropora colony.

Mechanical Filtration:

A pair of Deltec 902 needlewheel skimmers are the main workhorses of the system, running constantly. Their manufacturer's specifications claim they are capable of skimming a heavily stocked 1800 L (400 gallon) system, or a normally stocked 2500 L (550 gallon) system, so they are slightly underpowered for my system, and admittedly are not running at maximum efficiency due to low throughput. In hindsight, I would have opted for a different setup using a much larger skimmer with a higher flow rate, but for now I rely on the refugium to take up the slack in nutrient export.

Lighting & Zones:

Instead of the traditional method of bathing the entire tank in strong lighting, I opted to create zones for corals, reducing the total number of lights required and also saving some electrical expense in the process. I wanted to keep a variety of hard corals including light loving Acroporas and also LPS species which prefer less light, so prior to set up I designed the layout of the corals and the tank's construction in terms of placing the bracing straps and positioning the metal halides.

Photoperiod: Lights: 80 watt T5 Actinic x 2 54 watt T5 white x 4 400 watt MH x 4 On: 6:00 AM 7:00 AM 8:00 AM Off: 10:00 PM 08:00 PM 06:00 PM

Calcium and Carbonate Supplements:

I use a large "Schuran Jetstream 2" calcium reactor (below left). I fill this with various media, sometimes using purer sources such as AB hydro carbonate, sometimes just coral skeletal media such as coral gravel. A peristaltic pump pushes the effluent through the reactor, and a pH probe and module connected to the IKS computer trim the CO₂ injection to achieve the pH required, making life a lot easier.

An old salt bucket (right) is my "Bucket Kalk reactor" to feed the tank with limewater on a constant drip using another peristaltic pump. This feeds into a high flow area of the sump. Actually, I ordered a 6' tall acrylic reactor (the Beast) to be made at the same time the tank was built, but it is still AWOL. But that's another long story…

Computer Monitoring and Control:

I use the IKS unit with four pH modules (one to control the calcium reactor's CO2 solenoid, one to monitor the tank, and the remaining two to control two solenoids that feed CO2 into a pair of phytoplankton reactors). One temperature module runs and monitors the system.

Heating and Cooling:

With this much water and the fact that the whole system is effectively "outside" (the garage door is not sealed at all so it can be quite drafty in the fish room), I could not afford to heat the tank using the traditional electrical methods (I think it would have taken something like 4.2 KW worth of heaters for my water volume), so a central heating gas boiler is installed specifically for the tank.

A titanium heat exchanger is used to isolate the tank's water from the boiler's copper pipe works. To the boiler, the heat exchanger just looks like a radiator. The temperature module linked to the IKS computer switches a few relays that ask the boiler for heat when required.

Similarly, to avoid having to use a huge and powerful chiller with associated nuclear power station, I have a ground loop installed in the garden to cool the tank. This loop is nothing more than a long coil of micro-bore copper pipe buried a few feet down (even better if deep enough to get wetted by the water table) in the soil. It is connected to the boiler just like another "radiator" and exchanges heat with the tank via the titanium heat exchanger. A three-way valve, again controlled by the IKS computer, disconnects the ground part of the loop when the tank requires heat, and rejoins it again for cooling. It is connected this way instead of on an independent circuit as the pump inside the boiler circulates the water flow inside this heating/cooling loop, and some more control relays ensure that the boiler does not fire up the burners when in cooling mode.

In practice, during the hottest and driest spells of summer (we don't get many of these hot/dry days anyway), the ground itself becomes too hot and dry to dissipate the heat, so the cooling doesn't work for a couple of weeks a year. It works just fine the rest of the year, however, holding the tank at a fairly steady temperature. A few fans are employed during the really hot spells, and to make absolutely sure, another set of relays/contactors will turn off the main metal halide units if the tank begins to overheat.

Feeding & Maintenance Routine

The whole system pretty much runs without much intervention. As I don't even have an access hatch from the viewing room, I don't actually put my hands into the tank very often at all, which is a good thing. About ten times during the day an automatic feeder dispenses a mixture of dry flakes/pellets and Cyclop-eeze.

When I am home the fish are treated with a mixture of frozen food, about a tray's worth in volume of krill, and Mysis and plankton bought from the shop. I also make my own food consisting of a mix of mussels, cockles, squids, shrimps, etc. - whatever I can find at the supermarket.

During the tank's early months, I cultured live phytoplankton and rotifers and fed the tank heavily to boost it's microfauna population. For the last year or so I have not been able to do this but the inhabitants seem just as healthy and thriving all the same. I guess the system is maturing a bit more. Once or twice a week I add a stack of dry seaweed sheets (Nori from the Oriental supermarkets) to keep the herbivores in good shape.

Weekly or bi-weekly chores include emptying and cleaning the skimmers. Semi-annually the stream pumps get a thorough soaking in vinegar. The rest of the tasks, such as topping off the calcium reactor and Kalk reactor, are done as required.

About every six months or so, depending on my work schedule, I do a water change. Prior to this I give the tank and DSB a bit of a storm, blasting the rock surfaces with a powerhead. Detritus from these storms is either skimmed out or settles at the bottom of the sump. A quick run over with a wet/dry vacuum during the water change process easily removes these settlements.

Much of the maintenance is simplified with a key component of the system, one I could not do without, a washbasin in the fish room. No more sneaking into the kitchen dripping skimmate everywhere... no more, "HUSBAND! What's that SMELL?!"

Credits Where Credits are Due!

I can honestly say that without the help and inspiration of other reefkeepers on forums like Reef Central or UltimateReef, my aquarium would not exist. It is absolutely fantastic to find such experienced and knowledgeable people so willing to share and help others for little personal gain.

Also, my aquarium would not exist without my wife's blessing, help and support. She has been fantastic, having to grin and bear it through my obsessions, my spending and my ramblings. Her touch is evident throughout the entire setup, from the aquascaping to some of the fish selections. I would not be enjoying the tank without her.

Thank you for allowing me to share with everyone some of the pleasure of my reef aquarium, and perhaps someone may find some useful information to help him further his enjoyment of this wonderful hobby.

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