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The 4 Basic Needs of Corals

What Do Reef Corals Require to Survive?


Spotted Mushroom Coral

Actinodiscus / Discosoma species

Image by Shawn Richey

All corals have four basic needs required to survive -- water quality, food, light, and water movement. In general, hard or SPS/LPS corals are not as flexible as their soft coral cousins, making Mushrooms, Zoanthids, Polyps and Leather Corals some of the favorites for both novice and experienced reefkeepers alike.

Listed below are the 4 basic requirement categories of corals, each of which includes important points that pertain to them. However, keep in mind that corals can be finicky. Species within any given genus can have widely varied light, current, water quality, or other special needs, which makes it essential that any individual coral species be researched thoroughly before buying it.

    • Alkalinity
      • 3.2-4.5 meq/L considered optimum.
    • Temperature
      • 80-84°F
    • Salinity
      • 1.025 to 1.027 (specific gravity of natural sea water) is considered optimal.


    • Zooplankton
      • Requirements vary by coral species and plankton type (Phyto, Bacterio, Pseudo, Macro, Micro, Nano, and Pico).
    • Dissolved Organic Compounds
      • Although some corals derive nutrients from broken down organic matter suspended in the water column, DOCs should not be allowed to accumulate in excess, as this in turn leads to the build-up of nitrate in the aquarium. The use of a good quality protein skimmer helps to keep DOC levels down.


    • Requirements vary by coral species.
    • Soft corals generally require less light, while those hard corals that live by photosynthesis need more intense light.
    • For stony photosynthetic species, the lack of adequate lighting, as well as other environmental factors can result in coral bleaching.

    Water Movement

    • Requirements vary by coral species.
    • Some corals require a water surge to flush debris from their surfaces.

Care should be taken when mixing different corals in an aquarium. As an example: some corals do not "play well" with certain other coral types in a closed aquarium system. Many soft corals (i.e. Actinodiscus) should not be placed near most LPS/SPS corals, as they may have a detrimental effect on some hard corals.

It cannot be over stressed -- do the research before buying anything! That said, refer to 10 Easy Corals for a list of both soft and hard species considered by many marine aquarists to be among the easiest to keep in a reef tank.

  ~Stan & Debbie Hauter

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