Acropora Coral Care Guide

Acropora corals rank among the most challenging coral genera to maintain in home aquariums due to their sensitivity to water parameter fluctuations and demanding environmental requirements. Acropora typically thrives under high-intensity lighting of 250-400 PAR, strong turbulent flow, and exceptionally stable alkalinity, calcium, and magnesium levels. Reef keepers should establish their aquarium for at least 6-12 months before introducing Acropora, ensuring the system maintains consistent parameters without significant daily swings.

Acropora colonies reward patient aquarists who provide stable conditions with rapid growth and exceptional coloration, though the genus remains unforgiving of parameter instability or equipment failures.

Acropora corals grow faster than most other coral genera when provided with optimal conditions, with some healthy colonies capable of rapid branch extension. Acropora growth rates vary significantly between the 150+ species in the genus, with branching varieties like Acropora tenuis and Acropora millepora typically growing faster than tabling or encrusting forms.

Acropora colonies grow best with stable alkalinity above 8 dKH, calcium at 400-450 ppm, and consistent high lighting. Newly introduced Acropora frags often take 2-4 weeks to acclimate before visible growth begins.

Acropora corals turn brown when zooxanthellae populations increase excessively within the coral tissue, a response typically triggered by elevated nutrient levels or insufficient lighting intensity. Acropora browning commonly occurs in tanks with nitrate levels above 10 ppm or phosphate above 0.1 ppm, as excess nutrients fuel zooxanthellae reproduction that masks the coral's natural pigmentation.

Acropora frags recently introduced to a new system may brown temporarily as they acclimate to different lighting conditions. Reef keepers experiencing Acropora browning should verify PAR levels reach 250-400 at the coral's placement and consider reducing feeding or improving nutrient export through increased skimming or water changes.

Acropora corals suffer from Rapid Tissue Necrosis (RTN) and Slow Tissue Necrosis (STN) when bacterial infections, protozoan parasites, or environmental stressors overwhelm the coral's natural defenses. RTN in Acropora often involves Vibrio bacteria and Philaster parasites, causing complete tissue loss within 24-48 hours, while STN progresses over days or weeks with tissue gradually receding from the base upward.

Acropora colonies become vulnerable to tissue necrosis following temperature spikes, rapid alkalinity swings, or introduction of pathogens from new corals. Reef keepers can reduce RTN/STN risk by quarantining new additions, maintaining stable parameters, and promptly fragging affected colonies at least half an inch ahead of receding tissue.

Acropora corals typically thrive at PAR levels between 250-400 for optimal growth and coloration, with some shallow-water species tolerating up to 600 PAR when provided adequate nutrition and stable alkalinity. Acropora placement should target the upper third of the aquarium where lighting intensity peaks, though newly introduced colonies benefit from starting at lower positions around 150-200 PAR before gradual acclimation upward over 2-4 weeks.

Acropora corals receiving insufficient light below 200 PAR often brown out and grow slowly, while excessive light without proper acclimation causes bleaching as zooxanthellae are expelled. Most Acropora thrive with 7-9 hours of peak lighting daily, with gradual ramp-up and ramp-down periods simulating natural reef conditions.

Acropora Eating Flatworms (AEFW) prevention requires quarantining all new Acropora additions for 3-6 weeks with regular coral dips every 4-7 days using products like CoralRx or Revive. AEFW infestations devastate Acropora colonies by consuming tissue from the base upward, leaving characteristic bite marks and tan egg clusters visible under close inspection.

Reef keepers should examine new Acropora under magnification for flatworms that camouflage against coral tissue by ingesting zooxanthellae, appearing as 2-3mm oval disks matching the host's coloration. Dipping Acropora in a bowl of tank water with Lugol's solution and blasting with a turkey baster reveals hidden flatworms, and established tanks benefit from wrasse species that prey on adult AEFW.