Bali Green Slimer Acropora

Bali Green Slimer Acropora: The Fast-Growing SPS

The Bali Green Slimer Acropora (Acropora yongei) is one of the most popular and iconic Small Polyp Stony (SPS) corals in the reef aquarium hobby. Prized for its exceptionally fast growth rate and striking, consistent coloration, this coral grows in a dense, branching or staghorn morphology. It is a highly valued coral, as it is one of the easiest Acropora species to frag and propagate.

The Green Slimer is characterized by its vibrant neon green color across its body and polyps, and it often has purple or blue growth tips when thriving under intense light. Its name "Slimer" comes from the copious amounts of mucus it produces when stressed or handled, a defense mechanism common among Acropora species. This coral demands expert care, requiring immaculate and highly stable water chemistry, intense light, and turbulent water flow.

As a true Scleractinia (reef-building) coral, the Bali Green Slimer is a showpiece, but it is highly sensitive to fluctuations in alkalinity and is prone to various types of coral tissue necrosis (STN/RTN) if stressed.

Diet & Compatibility:

• Diet: This coral is primarily Photosynthetic. It hosts symbiotic zooxanthellae algae, which provide the vast majority of its energy needs through light.
• Feeding: While photosynthesis is key, supplemental feeding is highly beneficial due to its fast growth. Target feed the coral polyps 2-3 times per week with high-quality, fine particulate foods, such as cyclops, rotifers, or commercial coral powders. Shut off powerheads briefly during target feeding to allow the food to settle.
• Reef Compatibility: It is Reef Safe but requires careful placement. Like most Acropora, it can extend stinging mesenterial filaments to defend territory. It needs 6 inches or more of separation from soft corals and Large Polyp Stony (LPS) corals, as it will likely be chemically or physically damaged by them.
• Temperament: Peaceful toward fish and motile invertebrates, but Highly Aggressive/Territorial toward other corals. It thrives best in a dedicated SPS-dominant system.
• Water Requirements: Requires expert-level water stability with unwavering parameters: Alkalinity (dKH 8.0-9.0), Calcium (420-450 ppm), and Magnesium (1300-1400 ppm). Demands intense lighting (PAR 300-550+) and very strong, turbulent water flow to keep tissue healthy and prevent dead spots.

Quick Facts

• Scientific Name: Acropora yongei (often incorrectly sold as Acropora muricata)
• Primary Common Name: Bali Green Slimer Acropora
• Other Common Names: Green Slimer Acro, Green Staghorn Acropora, Acropora yongei
• Origin: Indo-Pacific (Bali, Fiji, Australia, Indonesia)
• Max Size: Can grow into large colonies (12+ inches in captivity)
• Temperament: Peaceful (Aggressive/Territorial toward other corals)
• Diet: Photosynthetic (Zooxanthellate; benefits from feeding)
• Minimum Tank Size: 75 Gallons (established, stable reef)
• Reef Compatibility: Yes, but requires expert-level spacing and stability.
• Care Level: Advanced / Expert