Reef aquarium

Alternatively, standard non-drilled aquariums employ an external "hang-on" overflow that feeds water via continuous siphon to the sump.

[3] These are often employed to augment the biological filtration by aiding in the reduction of nitrate, a waste product in an incomplete nitrogen cycle.

Deep sand bed opponents may prefer a "bare bottom" or "suspended reef" which allows for easier removal of nitrate-generating accumulated detritus.

It typically houses two main species of macroalgae, including Caulerpa prolifera or chaetomorphae or both (because these two strains are known not to spore but grow by rooting to propagate).

Macroalgae is used for two reasons: to remove excess nutrients from the water such as nitrate, phosphate, and iron, and to support beneficial microflora and fauna (zooplankton).

Small invertebrates (copepods and amphipods) are provided a space free of predation to grow and, when returned to the display tank, serve as food for corals and fish.

Conventional combined mechanical/biological filtration used in fish only systems is avoided because those filters trap detritus and produce nitrates which may stunt or even kill many delicate corals.

"Since flow speed is the critical measure for determining the rate of gas exchange, turnover does little to convey how fast a coral will respire and photosynthesize.

The pumps may be alternately switched on and off using a wave timer and aimed at one another or at the aquarium glass to create turbulent flow in the tank.

Drawbacks to the use of these powerheads include their capacity to clutter the display tank, propensity for excess heat production, and the laminar quality of water flow often produced.

Newer submersible propeller pumps are gaining popularity and are able to generate large volumes of turbulent water flow without the intensely directed laminar force of a power head.

Building water momentum using a gyre is an efficient method to increase flow, thus benefiting coral respiration and photosynthesis.

It is these zooxanthellae that require light to perform photosynthesis and in turn produce simple sugars that the corals utilize for food.

The challenge for the hobbyist is to provide enough light to allow photosynthesis to maintain a thriving population of zooxanthellae in a coral tissue.

Although their initial cost is much higher, they tend to be economical in the long run because they consume less power and have far longer lifespans than other systems.

Also, because LED systems are made of hundreds of very small bulbs, a microcomputer can control their output to simulate daybreak and sunset.

These corals require additional attention to water chemistry, especially maintenance of stable and optimal calcium, carbonate, and pH levels.

This equipment can allow for timely intervention in a potential disaster and provides an added sense of security for frequent travelers.

[6] Nano reefs have become quite popular in recent years among fish keeping hobbyists, primarily because of their smaller size, maintainability, and the possibility of lower costs.

Nano reefs are very commonly sold as complete kits which contain the tank, stand, power compact T5, T8, PL lamps or metal halide lighting, protein skimmer, UV steriliser, 3 or more stage filtration, a heater and a water pump or powerhead.

Pico reefs often consist of live rock, hardy corals, and small invertebrates such as hermit crabs and marine snails.

The keeping of pico reef aquariums has tested the extent of allelopathy, the chemical and physical means by which corals compete for space.

Before the advent of these concentrated environments, it was thought to be impossible for corals of even a few mixed genera to occupy such a small shared water volume.

There are two major factors to be considered: biological load, i.e., the ability of the tank to process the wastes produced by the occupants, and species compatibility.

For this reason, smaller species of fish, such as gobies and clownfish, are popular choices because of their relatively small size and ability to coexist peacefully with other tank inhabitants.

Other nano reef aquarists use devices such as protein skimmers to remove excess waste from the aquarium, before it has a chance to be broken down to nitrate.

[9] Removing the excess wastes mechanically can reduce the frequency of water changes needed to keep nitrate levels low.