How to Make Your Own Coral Decor

Living corals are exquisitely colored and shaped and give a natural look to any marine aquarium. Corals demand a very high water quality though, and require lighting of the correct spectrum and intensity. Living corals also need to feed on plankton and many marine fish species. Sea water hobbyists can, however, make their own artificial coral, which will still give a naturalistic look to the aquarium and provide hiding and resting places for the fish and invertebrate animals, such as urchins and starfish.

Things You'll Need

  • Plaster powder
  • Spoon
  • Bowl
  • Water
  • Coral shaped molds
  • Craft knife
  • Paper towel
  • Coral identification book
  • Acrylic paint
  • Paint brushes
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Instructions

    • 1

      Slowly mix two parts of plaster powder into one part of water. Add the powder slowly and stir very well. Ensure that your mixture is thick but still runny enough to pour out of the spoon. Artificial coral made from watery plaster will take longer to dry but are typically lighter in weight.

    • 2

      Spoon the mixture into your coral mold, which will be available from specialist aquatic stores and some craft shops. Tap the sides of the mold to force air out of the plaster mixture.

    • 3

      Put the mold aside and allow the plaster to set correctly. Your coral mold will normally take anywhere between 30 and 60 minutes to dry. Test if your plaster mold is ready to be removed by gently touching the exposed plaster. The piece of coral is ready to be removed from the rubber mold once it is firm.

    • 4

      Carefully peel the rubber mold away from the plaster coral shape. Take extra care if the shape is branched and has numerous pieces radiating from a central shape.

    • 5

      Use a craft knife to remove any excess plaster around the edges of your coral shape. Although the plaster will be firm at this stage, you will still be able to break away or smooth out any unnecessary pieces of plaster with your fingers.

    • 6

      Place the piece of plaster coral in the sun or on a radiator to dry completely.

    • 7

      Paint your plaster coral using acrylic paint that is inert in water once totally cured. Use a coral identification book to ensure that your colors are correct. Leave the artificial coral for a number of days so the acrylic paint can cure completely.

    • 8

      Use a paper towel and clean out your mold so you can use it again. Discard left over plaster in the refuse bin and do not attempt to flush it down the sink, as excessive amounts will clog the pipes.