{"id":7121,"date":"2026-02-17T06:51:13","date_gmt":"2026-02-17T06:51:13","guid":{"rendered":"https:\/\/aquadistribution.co.uk\/product\/horn-hard-coral-hydnophora-sp\/"},"modified":"2026-02-17T06:51:14","modified_gmt":"2026-02-17T06:51:14","slug":"horn-hard-coral-hydnophora-sp","status":"publish","type":"product","link":"https:\/\/aquadistribution.co.uk\/?product=horn-hard-coral-hydnophora-sp","title":{"rendered":"Horn Hard Coral Hydnophora Sp"},"content":{"rendered":"

Horn Hard Coral (Hydnophora sp.)<\/strong><\/h2>\n

(Also known as Horn Coral, Branching Horn Coral, or Knob Coral)<\/em><\/p>\n

Overview<\/strong><\/h3>\n

The Horn Hard Coral (Hydnophora<\/em> sp.) is a striking small-polyp stony (SPS) coral<\/strong>, instantly recognisable by its horn-like branches<\/strong> and distinctive, raised polyp ridges<\/strong> that create a textured, sculptural appearance. Typically bright green, yellow-green, or teal<\/strong>, this coral exhibits intense fluorescence under blue or actinic lighting. While hardy and fast-growing under stable conditions, Hydnophora<\/em> is highly aggressive<\/strong> toward nearby corals and requires thoughtful placement. Its branching or encrusting growth patterns make it a bold, architectural addition to established reef aquariums.<\/p>\n

Origin<\/strong><\/h3>\n

Native to the Indo-Pacific region<\/strong>, including the Great Barrier Reef, Coral Sea, Fiji, Tonga, Indonesia, and the Red Sea<\/strong>. Found in shallow reef slopes and outer reef crests<\/strong>, where it receives strong light and vigorous water movement.<\/p>\n

Feeding<\/strong><\/h3>\n

The Horn Coral is photosynthetic<\/strong>, deriving most of its energy from zooxanthellae<\/strong> living within its tissue. It also benefits from supplemental feeding to boost growth and colouration. Feed 1\u20132 times per week<\/strong> with:<\/p>\n

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  • \n

    Microplankton or marine snow<\/p>\n<\/li>\n

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    Finely powdered coral foods<\/p>\n<\/li>\n

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    Phytoplankton or SPS-targeted coral blends<\/p>\n<\/li>\n<\/ul>\n

    Feed during periods of moderate flow so fine foods can settle gently over the coral surface.<\/p>\n

    Lighting<\/strong><\/h3>\n

    Moderate to high lighting.<\/strong> Hydnophora<\/em> thrives in bright light conditions provided by LED, T5, or metal halide<\/strong>systems.<\/p>\n

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      PAR range: 200\u2013350 \u00b5mol\/m\u00b2\/s<\/strong><\/p>\n<\/li>\n

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      Gradually acclimate to intense lighting to prevent bleaching.<\/p>\n<\/li>\n

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      Blue-spectrum lighting enhances fluorescence and contrast along the polyp ridges.<\/p>\n<\/li>\n<\/ul>\n

      Water Flow<\/strong><\/h3>\n

      Moderate to strong, turbulent flow.<\/strong> This coral benefits from alternating current patterns that keep surfaces clean and encourage polyp extension. Avoid direct, laminar jets that could cause tissue erosion.<\/p>\n

      Placement<\/strong><\/h3>\n
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        Place on mid to upper rockwork<\/strong> where it receives strong, indirect light and good flow.<\/p>\n<\/li>\n

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        Provide 15\u201320 cm (6\u20138 inches)<\/strong> of space from neighbouring corals \u2014 Hydnophora<\/em> is extremely aggressive<\/strong> and will extend long, stinging sweeper tentacles<\/strong> that can kill nearby species.<\/p>\n<\/li>\n

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        Ensure rockwork is secure, as rapid encrusting growth can attach firmly to surfaces.<\/p>\n<\/li>\n<\/ul>\n

        Tank Mates<\/strong><\/h3>\n

        Reef safe with caution.<\/strong> Compatible with:<\/p>\n

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        • \n

          Peaceful reef fish (clownfish, tangs, gobies, wrasses, etc.)<\/p>\n<\/li>\n

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          Invertebrates such as snails, shrimp, and hermit crabs<\/p>\n<\/li>\n

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          Other SPS corals at a safe distance<\/p>\n<\/li>\n<\/ul>\n

          Avoid:<\/p>\n

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          • \n

            LPS or soft corals nearby (they will be stung and damaged)<\/p>\n<\/li>\n

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            Aggressive or stinging species in close proximity (e.g., Galaxea, Euphyllia)<\/p>\n<\/li>\n

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            Large angelfish or butterflyfish that may pick at coral tissue<\/p>\n<\/li>\n<\/ul>\n

            Aggression<\/strong><\/h3>\n

            Highly aggressive.<\/strong> Hydnophora<\/em> possesses powerful stinging tentacles and can cause severe tissue necrosis in nearby corals. Keep it isolated or in a dedicated section of the reefscape.<\/p>\n

            Experience Level<\/strong><\/h3>\n

            Intermediate to advanced.<\/strong> The Horn Coral is durable and fast-growing but requires stable water chemistry and careful spatial management due to its aggression. Suitable for aquarists experienced with SPS or mixed coral systems.<\/p>\n

            Water Parameters<\/strong><\/h3>\n
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            • \n

              Temperature:<\/strong> 24\u201327\u00b0C (75\u201381\u00b0F)<\/p>\n<\/li>\n

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              pH:<\/strong> 8.1\u20138.4<\/p>\n<\/li>\n

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              Salinity:<\/strong> 1.024\u20131.026 SG<\/p>\n<\/li>\n

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              Alkalinity (dKH):<\/strong> 8\u201312<\/p>\n<\/li>\n

            • \n

              Calcium:<\/strong> 400\u2013450 ppm<\/p>\n<\/li>\n

            • \n

              Magnesium:<\/strong> 1250\u20131350 ppm<\/p>\n<\/li>\n

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              Nitrate:<\/strong> <5 ppm<\/p>\n<\/li>\n

            • \n

              Phosphate:<\/strong> <0.03 ppm<\/p>\n<\/li>\n

            • \n

              Tank Size:<\/strong> Minimum 150 litres (40 gallons)<\/strong>; larger systems preferred for stable chemistry and spacing<\/p>\n<\/li>\n<\/ul>\n

              Stable calcium, alkalinity, and nutrient levels are critical for skeletal strength and vibrant colouration.<\/p>\n

              Reef Compatibility<\/strong><\/h3>\n

              Reef safe with caution.<\/strong> The Horn Hard Coral adds dramatic shape and fluorescence to SPS or mixed reefs but must be placed with ample space<\/strong> to prevent damage to nearby species. Its aggressive nature makes it best suited as a solitary showpiece coral<\/strong> in the upper reef structure, where it can grow freely and display its natural brilliance<\/p>\n","protected":false},"excerpt":{"rendered":"

              Horn Hard Coral (Hydnophora sp.) (Also known as Horn Coral, Branching Horn Coral, or Knob Coral) Overview The Horn Hard Coral (Hydnophora sp.) is a striking small-polyp stony (SPS) coral, instantly recognisable by its horn-like branches and distinctive, raised polyp ridges that create a textured, sculptural appearance. Typically bright green, yellow-green, or teal, this coral […]<\/p>\n","protected":false},"featured_media":7120,"template":"","meta":[],"product_brand":[],"product_cat":[74],"product_tag":[],"class_list":{"0":"post-7121","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-hard-corals","8":"first","9":"instock","10":"taxable","11":"shipping-taxable","12":"purchasable","13":"product-type-simple"},"group_of_quantity":0,"min_quantity":0,"max_quantity":"","exclude_order_quantity_value_rules":"no","exclude_category_quantity_rules":"no","combine_variations":"no","exclude_global_add_ons":[],"addons":[],"_links":{"self":[{"href":"https:\/\/aquadistribution.co.uk\/index.php?rest_route=\/wp\/v2\/product\/7121","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/aquadistribution.co.uk\/index.php?rest_route=\/wp\/v2\/product"}],"about":[{"href":"https:\/\/aquadistribution.co.uk\/index.php?rest_route=\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/aquadistribution.co.uk\/index.php?rest_route=\/wp\/v2\/media\/7120"}],"wp:attachment":[{"href":"https:\/\/aquadistribution.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=7121"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/aquadistribution.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fproduct_brand&post=7121"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/aquadistribution.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fproduct_cat&post=7121"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/aquadistribution.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fproduct_tag&post=7121"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}