Given that the aquarium is nothing more than a sealed box, we are somewhat limited by what we can do to create water motion. Typically aquarists will use a combination of submersible pumps, powerheads, external pumps, and other such devices to circulate the water in their aquarium.

Submersible and external pumps are often placed either in the sump beneath the aquarium as the return path, or on a closed loop path through which the water flows.  The return line from the sump, while capable of creating water motion with carefully aimed exhaust streams, is secondary to water motion and primarily used as part of the sump system. Additionally, submersible pumps in the sump will introduce some degree of heat into the system. On the other hand, closed loops are purely dedicated to moving water around the aquarium.

To create a closed loop, aquarists often drill several holes in the back of their aquarium through which bulkheads are attached. The input to an external pump is connected to one of the holes, and the output of the pump is connected to the other holes. This creates a specifically plumbed loop for water to flow through. As water returns to the aquarium from the pump, the water is aimed in the direction desired using flow manipulation devices. Closed loops are a powerful way of moving water around a reef aquarium without introducing any heat from the pump to the water column.

Powerheads are a more common method of moving water around the aquarium. They are placed directly into the aquarium, and yes, they will introduce heat as well. Powerheads can be readily aimed wherever the current is desired. They come in various sizes and powers ranging from small pumps geared towards nano aquariums, to larger pumps designed to move large swaths of water across the tank. For Tank 1.0, 4 MaxiJet 600s were chosen to move water around the aquarium. These were then replaced with MaxiJet 1200s when the wavemaker was introduced, see below.

The placing of the waterheads is as important a choice as the type. Depending on the types of corals, and other organisms, in the aquarium, the goal of water movement ranges from using a gentle flow to eliminate dead spots in the tank in which detritus can collect to turning over the water volume of the tank 30-50x per hour. The general rule of thumb for most reef aquarium is at least a 10x turnover with minimal dead spots. This means that for a 50 gallon aquarium, the water movement should be a dedicated 500gph worth of closed loops and/or powerheads in the aquarium.

Equally important is the randomness of the water. The ocean is does not constantly flow from left to right, similarly the aquarium should not constantly flow in one direction. The powerheads should be arranged to create as much chaotic water motion as possible. Devices known as wavemakers can be employed to help introduce randomness into the system. These devices come in mechanical and electronic versions. The mechanical versions, such as the SCWD, have gears and impellers in them and periodically shift flow of water from one port to another. SCWDs typically cost upwards of $35.

The electronic wavemakers, such as the Red Sea WaveMaster Pro, control power going into the pumps and turn them on/off as needed in a random fashion. The WaveMaster sells for around $150 and was chosen for Tank 1.0. One thing to keep in mind is that a wavemaker will run not run the pumps all of the time. This means that the maximum rated waterflow of the pump is not what you will be acheiving as the device turns pumps on and off. On Tank 1.0, the original Maxijet 600s which were selected were traded in for MJ12s once we realized that at any given time only 2 of them would be on. This allowed us to maintain at least 590gph of water movement at all times.

That concludes the post at this time, we hope that you will come back to join us and learn about our reef aquariums.

In a closed aquatic system, such as any home aquarium, any nutrients readily available either live or grow there. The owners periodically feed the inhabitants some manner of fresh, frozen, or freeze-dried cuisine to the inhabitants in an effort to sustain them. Any excess food falls typically past the swimmers in the water column, into the depths where it is consumed by the scavengers and other similar inhabitants. Anything not eaten falls into various nooks and crannies in the rocks and substrate of the aquarium. Much like food left open in the air for an extended time, excesses food in a marine environment begins to decompose.

In any system, both decomposing food and waste produced by the tank inhabitants are converted by bacterium into a toxic chemical known as NH4 or, more commonly, ammonia. In even small amounts, this ammonia readily kills the inhabitants of most aquaria. Nitrosomonas bacterium, a species of bacteria that eats ammonia, devour the ammonia and produce NO2, or nitrite, as their waste product. While organic, nitrite is still toxic to aquarium inhabitants. Nitrobacter bacterium, a species of bacteria that eats nitrite, consume the NO2 and produce NO3, nitrate, as waste. Nitrate is more readily known as a common plant fertilizer.Nitrate is not a toxin in the same manner as ammonia and nitrite.

Most inhabitants are able to handle a reasonable amount of nitrate, fish better than invertebrates. At high levels nitrate begins to alter the environment and render it inhospitable by causing chemical changes to the water. At very high levels, the nitrate renders the water toxic. In general, nitrate levels are something an aquarist can tend to using any or all of the methods from the three schools of thought of reef keeping. It is important to note that none of the three methods is fixed in stone and their use and adaptation are reasonably flexible.

Reef aquaria today typically contain several inches of sand on which sit many pounds of rocks that came from the sea. The rocks are large and numerous and consume close to 50% of the volume of the aquarium. These porous rocks arrive from parts of the world such as Fiji, St Martial Islands, and Papa New Guinea, and are covered with various algae, plants, and marine life. Each of these organisms plays a role in the mariner environment; however, it is the smaller organisms, those invisible to the naked eye that are within the rocks that make all the difference.

The porous nature of the rock allows for surface areas greater than that of the exterior of the rock. The large surface area provides homes for the Nitrobacter bacterium. These bacteria consume the nitrate and produce nitrogen (N2) as waste. The removal of nitrate, or denitrification, by the bacteria in the rock makes it an essential component in completing the nitrogen cycle. Because the bacteria live well within the rocks, the water in the aquarium must be circulated with sufficient force that some part of it reaches the center of the rocks.This mix of a sand and live rock with water movement circulation throughout the tank is known as the berlin method.

The Jaubert method substitutes the live rock for an sand bed which often ranges in 6-8" and is established over a plenum of some kind, usually an old undergravel filter. The goal is to have the bacteria colonize the deep sand bed and provide the same denitrification as the live rock. In both the Jaubert and Berlin methods, protein skimmers are an essential part of the filtration system.

The thirds camp of biological filtration is the algal turf scrubber. To accomplish this, water is routed from the aquarium into shallow trays in which turf algae are cultured. The algae growing in the trays use the nitrate in the water as their food source. The algae are then harvested as needed providing the export path of the waste.

For Tank 1.0, we decided to employ the Berlin method and have a 2-3" sand bed with 65 lbs of live rock in our aquarium. We hope that you will continue to follow along and learn about our reef aquarium.

There is a serious downside of mechanical filtration in the reef aquarium that is less prevalent in fish only tanks or even freshwater, that is the need to frequently change the medium in the filtration unit or risk a nitrate bloom in one's tank. This can result in occurrences such as algae blooms or at very high levels of nitrogen, total tank failure. Typically the material needs to be changed every 2 weeks (conservative) to every 4 weeks (aggressive) before the decomposing material caught in the filter begins to decompose to the point of producing nitrate and ammonia.

The risks of using mechanical filtration without a frequent change are quite weighty. However, since we are space constrained on Tank 1.0 and will not have a sump, we decided to use a small HOB filter for the sole purpose of mechanical filtration as a water polisher and to give us a place to put chemicals, such as carbon, for use in the tank. The filter will run empty most of the time only being used with media when the water shows signs of yellowing or if particles are obviously visible. The filter will also be used in conjunction with regular water changes.

The chosen filter was an aquaclear 70 rated for up to a 70 gallon tank. This was readily available at a local pet store for around $45.

Check back with us soon for our next installment on chemical filtration and the reef aquarium.

The T5s have a nice solid light output, they're relatively inexpensive, and are suitable for corals requiring moderate to high light levels. A set of lights for our 36" tank would have cost about $200 from several online retailers.

VHO and Power Compact tubes are suitable for low to moderate light requiring corals such as leathers, mushrooms, and SPS. A retrofit 36" PC unit for installation into the canopy purchased with Tank 1.0 was $99 from several online retailers.

Metal Hydride lighting is suitable for corals requiring intense lighting. This light is the strongest and most intense of the bunch with a higher cost and power requirement. They also produce the most heat of all the lighting types. The MH lighting which we looked at was in excess of $400. This was deemed to costly for the 1.0 reef aquarium.

LED lighting is the newest lighting type on the scene. The LEDs are very focused in the color spectrum which they emit so they can target the lighting specifically within the wavelength required. They have the lowest power consumption of all the lighting types, have the longest lasting bulbs, and produce practically no heat. They downside to them is that they are new so that people don't have experience raising coral under then, and they are exceptionally expensive.  While we would loved to have had them, the $1200 price tag put them clearly outside of our reach.

For tank 1.0, it was decided to go with Current USA SunPaq Power Compact retrofit kits and installed 2 of them into the canopy. We have to change the bulbs every 8-12 months as PC bulbs are said to color shift. (If anyone can find actual documentation supporting this we'd love to see it.) We knew we would be sticking with the simpler soft corals to start and would upgrade the light kit for tank 2.0.

Thanks for reading and following us on our journey to build our reef aquarium.

Glass aquariums are cheap, readily available, and do not scratch easily. They are however quite heavy in larger sizes, requiring more than two people to move a tank much larger than a 55 gallon aquarium, and are quite expensive if custom glass is used as the main viewing glass.

Acrylic aquariums are exceedingly light, strong, and offer superior visual characteristics. They are much more expensive when compared to glass, and scratch very easily making it difficult to keep the inside viewing glass clean without taking precautions with the cleaning tools.

Beyond these two choices you can choose to have the tank predrilled, or to have internal overflows in the aquarium. An overflow allows water to flow out of the tank down into a second tank commonly known as the sump. The sump would then contain additional equipment such as heaters, skimmers, mechanical filtration devices, etc., kept out of site and not in the display tank.

Additionally, common footprints for the aquariums are 36, 48, 60, and 72" in length, and varying in dept between 12, 18, and 24 inches, and in height between 18 to 24 inches.

Due to space constraints, for Tank 1.0 an All Glass brand 45 gallon 36x12x24" aquarium that was not predrilled was chosen as the display tank. This is the basis for our reef aquarium.

1.    Tank
2.    Lighting
3.    Mechanical Filtration
4.    Chemical Filtration
5.    Biological Filtration
6.    Water Movement
7.    Heating/Cooling
8.    Water testing

Each of these components will receive its own post detailing what it entails and what we’ve decided to go with for on our own aquariums.

Thanks for reading and check back soon to read more about our journey with our reef aquarium.

If you would like any additional specific information on a topic that is covered here, please let us know via the comments and we will write a post about that topic. Thanks again for the visit and be sure to check back often for more information on reef aquariums.