New corals can look fine in the bag. They can still crash after a fast transfer. A steady acclimation routine lowers stress and prevents tissue loss.
This step-by-step guide fits most reef tanks. It uses simple tools and clear checkpoints. You will also learn what to skip and why.
Section 1: Prep your tank and coral before opening the bag
Start with stable tank parameters. Aim for 1.025 specific gravity, 25–26°C, and pH 8.1–8.4. Keep alkalinity 8–9 dKH, calcium 400–450 ppm, and magnesium 1250–1400 ppm.
Turn off display lights or set them to 10–20% intensity. Reduce flow to a gentle sway. This prevents immediate light shock and tissue tearing.
Set up a clean acclimation container. Use 1–2 liters of bag water plus the coral. Keep the coral submerged at all times.
Gather tools before you cut the bag. Use a thermometer, refractometer, and airline tubing. Keep coral cutters, gloves, and paper towels nearby.
- Match temperature within 0.5°C before any drip acclimation.
- Confirm salinity in the bag and in the tank.
- Prepare a low-light spot on the sand bed for placement.
If you need a refresher on targets, review reef tank water parameters. If fish are new too, read quarantine basics. These steps prevent surprises later.
Section 2: Drip acclimation, dipping, and safe placement
Float the sealed bag for 10–15 minutes. This equalizes temperature fast. Then open the bag and pour water and coral into the container.
Measure bag salinity with a refractometer. If bag salinity differs by more than 0.002 SG, use drip acclimation. Start a siphon with airline tubing and a knot valve.
Drip at 2–4 drops per second for most corals. Target 30–45 minutes for LPS and SPS. For soft corals, 20–30 minutes often works.
Stop when container salinity matches the tank within 0.001–0.002 SG. Remove half the water once during the process. This keeps the container from overflowing.
- If bag salinity is 1.020 and tank is 1.025, drip for 45–60 minutes.
- If bag salinity is 1.024 and tank is 1.025, drip for 15–25 minutes.
- Never drip for hours in cold rooms. Temperature can drop quickly.
Next, dip the coral to reduce pests. Use a coral dip product at label dose. Use a separate dip cup with tank water, not bag water.
Dip time is often 5–10 minutes. Gently baste the coral with a turkey baster. Look for flatworms, nudibranchs, and pods dropping off.
Rinse the coral in a second cup of clean tank water. Then place it in the display. Start on the sand bed for 3–7 days.
Move the coral up in small steps. Raise it 2–3 inches every 3–4 days. Watch for bleaching, retraction, or brown jelly.
Optional Section 3: Troubleshooting and common mistakes
Skip “bag water into the tank.” Bag water can carry pests and waste. It can also contain high ammonia after shipping.
Do not chase perfect numbers during acclimation. Stability matters more than rapid correction. Avoid large alkalinity changes in one day.
If a coral stays closed for 24 hours, check flow and light first. Verify temperature and salinity next. Then test alkalinity, nitrate, and phosphate.
Use these quick ranges for mixed reefs. Keep nitrate 5–15 ppm and phosphate 0.03–0.10 ppm. Ultra-low nutrients can pale new frags.
- Bleaching in 48 hours often means too much light. Lower intensity by 20%.
- Receding tissue can mean alk swings. Limit changes to 0.5 dKH per day.
- Brown jelly on LPS needs action. Siphon, dip, and increase gentle flow.
Build a repeatable routine and log each coral. Note bag salinity, dip time, and placement. For pest prevention, see coral pest identification.
Sources: Borneman, E. “Aquarium Corals” (TFH); Delbeek & Sprung, “The Reef Aquarium” Vol. 1–3; Julian Sprung, “Corals: A Quick Reference Guide.”
Coral acclimation is a slow, careful handoff. Match temperature and salinity first. Then dip, place low, and ramp up light over days.
With stable parameters and good notes, most frags settle fast. You will also catch pests early. That protects every coral in your reef.
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