How to Acclimate New Corals: Drip Method, Light Adjustment and Placement
Bringing new corals home is exciting, but the transition from a shop’s holding system to your reef can shock sensitive specimens into bleaching or tissue recession if handled carelessly. Understanding how to acclimate corals properly protects your investment and gives every new addition the strongest start. At Gensou Aquascaping, 5 Everton Park, Singapore, we follow a consistent acclimation protocol for every coral we place into client tanks — whether it is a $15 SGD zoanthid frag or a $300 SGD Acropora colony.
Temperature Matching First
Float the sealed bag in your sump or a container of tank water for 15 to 20 minutes. This equalises temperature gradually, which is especially important when corals travel in Singapore’s air-conditioned cars then enter a tank at 26 to 27 degrees Celsius. Never rush this step. A rapid temperature swing of even 2 degrees Celsius can trigger mucus sloughing in LPS corals or polyp retraction in SPS colonies that takes days to recover from.
The Drip Acclimation Method
After temperature matching, open the bag and place the coral with its transport water into a small container. Use airline tubing with a knot tied loosely to create a drip — two to three drops per second from your tank into the container. Over 30 to 45 minutes, the water volume in the container roughly doubles, gradually adjusting the coral to your tank’s salinity, pH, and alkalinity. This slow transition is critical when your tank parameters differ significantly from the shop’s system. Discard the mixed water afterward rather than pouring it into your display — transport water often contains elevated ammonia and potential pathogens.
Inspecting for Pests
Before placing any coral in your reef, inspect it thoroughly under strong light. Look for Acropora-eating flatworms, montipora-eating nudibranchs, and small crabs hiding among branches. A coral dip using products like CoralRx or Bayer insecticide (diluted appropriately) for five to ten minutes dislodges most hitchhikers. Swirl the coral gently during the dip and use a turkey baster to blast crevices where pests hide. Rinse in a separate container of clean tank water before placement. This step alone prevents the majority of pest introductions that plague reef tanks.
Light Acclimation for SPS and Sensitive Corals
Corals kept under lower light at the shop need time to adjust to your reef’s higher PAR levels. Place new SPS corals on the sand bed or a lower frag rack for the first week, then move them halfway up the rockwork for another week before positioning them in their final spot. Alternatively, reduce your light intensity by 30 per cent for three days after adding new corals, then ramp back to normal over a week. Skipping light acclimation is the most common cause of bleaching in newly purchased Acropora and Montipora specimens.
Flow Considerations During Placement
Each coral species has a preferred flow regime. SPS corals like Acropora and Stylophora want moderate to strong random flow that keeps tissue clean without directly blasting a single point. LPS corals such as Euphyllia species prefer gentler, indirect flow that allows their tentacles to sway without folding over. Soft corals and mushrooms tolerate low to moderate flow. When placing a new coral, observe how its polyps respond over 48 hours — retracted polyps or tissue pulling away from the skeleton often signals excessive flow at that position.
Placement and Spacing
Corals need adequate space between neighbours to avoid chemical warfare. Many species release terpenoid compounds that damage nearby colonies of different genera. Keep at least 5 cm between frags of different species, and significantly more between aggressive genera like Galaxea, Euphyllia, and Hydnophora, which extend sweeper tentacles up to 15 cm at night. Use reef-safe epoxy or cyanoacrylate gel to secure frags to rock — unstable corals that tumble in current suffer tissue damage and often fail to recover.
Monitoring After Introduction
Watch new corals closely for the first two weeks. Healthy signs include polyp extension within 24 to 48 hours, natural colouration, and visible feeding response. Warning signs — bleaching edges, tissue recession from the base, excessive mucus production, or persistent polyp retraction — indicate stress from parameters, light, flow, or aggression from neighbouring corals. If a coral shows stress, move it to a lower-light, lower-flow area before the damage becomes irreversible. Patience during the acclimation window pays dividends in long-term coral health and growth.
Building Good Habits
Consistent acclimation protocol protects every coral you add, regardless of price or perceived hardiness. Even hardy zoanthids and mushroom corals benefit from drip acclimation and pest dipping. Over time, these habits become second nature — a five-minute coral dip and a 30-minute drip session are minor investments compared to the cost of replacing a coral lost to preventable acclimation stress. Treat every new coral with care, and your reef will reward you with growth and colour that make the effort worthwhile.
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emilynakatani
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