• Marine water aquariums

    Magnificent coral reefs, shimmering fish, a lively bustle of bright hues and shifting shapes and colours. A marvellous and exotic underwater world which is attracting new enthusiasts all the time: marine water – or reef – aquariums are becoming increasingly popular.

Marine water aquariums – a special fascination

Fresh or marine water aquariums – what’s the difference?
In a freshwater aquarium fish and other occupants live in a state of symbiosis with plants. The water comes out of the tap and has to be filtered and processed but, basically, everything is straightforward. Thanks to their relatively uncomplicated equipment and the fact that they are comparatively simple to look after, freshwater aquariums are also suitable for beginners. The outlay is within limits.  

Marine water aquariumsare rather more demanding. First the tap-water must be purified and enriched with salt. Caring for corals and other animals requires more attention, a lot of patience and more expensive equipment. It is only partly true to say that marine water or reef aquariums mean a lot of work, because in recent years quite a lot has happened. New discoveries about the sensitive eco-system of a coral reef and technical advances have made a lot of things much simpler. Even beginners can keep a reef aquarium if they abide by the rules.



A few basic concepts which you should be familiar with
If you speak to an aquarium-keeper or read up on the subject, you will frequently come across various terms which are seldom further explained. This results in confusion and misunderstanding, so here are a few definitions:

Marine water or reef aquariums
Saltwater or seawater aquarium is actually the general term for any aquarium which is used with saltwater (including specialised types such as North Sea, Mediterranean and mangrove aquariums etc.) There are pure fish aquariums (occupied solely by fish), as well as aquariums for invertebrates (e.g. nano aquariums), but what is usually meant is a reef or coralreef aquarium. This is a tropical marine water aquarium in which corals form a close living community (this is known as biocoenosis), with fish, crabs, echinoderms (creatures with spines) and a large number of micro-organisms and small animals.  

Corals and coral reefs
Corals are not plants, as many believe, but colonies of tiny sessile (“tight-sitting”) coelenterates, which include sea anemones and jelly fish. In an aquarium it is mainly reef-forming stony corals that are used. They secrete calcium and eventually form skeletons. The dead skeletal material is regularly overgrown with living tissue and this is how coral reefs are eventually formed. Over thousands of years huge reefs and islands were formed in this way, including the Bahamas, Bermuda and the Maldives.
Tropical stony corals (sometimes called soft corals or leather corals, amongst other things) derive their nutrients chiefly from small, single-cell algae (zooxanthellae), which settle symbiotically in their tissue. In a well-lit marine water aquarium, corals can survive and grow for years without feeding.
As well as “zooxanthellate” corals there are several other types but they feed on each other and are not easy to keep in an aquarium for beginners.

Live rocks
In the world of aquariums “live rock” means pieces of reef in which plant and animal organisms live. When the aquarium is being set up, they introduce sediments, bacteria, a variety of small life forms including crustaceans, feather duster worms, algae and sponges into the aquarium. It is only with these organisms that the eco-system can function effectively in the marine water aquarium. They are a natural bio filter and process the water.