Corals 1

Depending on your outlook, corals in our tanks are "the reason for it all", or "The cherry on top". Whatever your view, keeping corals successfully is a challenge which few serious marine aquarists can resist.

Because most corals have symbiotic Zooxanthellae (algae living inside the corals), and there is so much technical talk on suitable lighting spectrums and intensities, one tends to forget that corals are actually predators (and very successful ones at that). In fact, of all the predators on Earth, corals have the largest part of their bodies devoted to catching food. Of course, most corals also need light of a suitable colour spectrum and intensity, adequate water movement, and very good water quality. Without a suitable "total system" one will never achieve long term success with any of the so called Hard Corals.

Soft Corals, such as the Leather corals (Sinularia, Sarcophyton and Lobophytum sp), Mushrooms (Discosoma sp.) and "Polyps" (Zoanthids) are all rather easy to keep. They require good water movement, but do not require such intense lighting as hard corals. They do thrive under strong lighting, though, if they are slowly acclimated. As you can see from the photos, mine are doing very well under the 2x150W metal halide lighting.

Corals tend to change shape between their "Day-mode" (mainly photosynthesizing), and their "Night-mode" (actively "hunting" to catch prey), as the following photos clearly illustrate: