Coral Acclimation & Dipping guide
A new coral can look clean and still carry pests, parasites, algae or disease. Many reef disasters start with a single frag with hitchhikers that spread before you notice them.
Acclimate first so the coral can handle the chemistry and light. Then dip it outside the tank to knock pests off before it goes in.
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What you will need
Dip outside the tank · Each dip will be different so follow directions on the bottle
Have two clean containers, tank water, and a dip mixed to the manufacturer’s dose. Gloves and eye protection are worth it — dip solutions are strong.
Gear
Coral dips
Why acclimate your new coral
Chemistry, light and flow · Change them slowly
Acclimation is the slow introduction to your tank’s water, temperature, lighting and flow. Corals react badly to sudden swings.
Float the sealed bag 15–20 minutes before you open it.
A sudden SG jump can shred tissue. Mix tank water in slowly.
Fast swings stress polyps and can start recession.
Start lower than the final spot. Move it up over days, not hours.
Indirect flow first. Direct blast on a newly dipped coral is extra stress.
Recession, bleaching, retracted polyps, stalled growth and disease.
Basic acclimation steps
Temperature first · Dip before it goes in
Float the sealed bag
15–20 minutes in the tank equalises temperature. Leave it sealed.
Open and inspect
Look for tissue damage, pests on the plug, and odd film before you mix water.
Add tank water slowly
Small amounts over 20–30 minutes. Discard bag water — do not pour it into the reef.
Dip, then place low
Dip in a separate container (steps below). Then start the coral in lower light and move it to the final spot over several days.
What dipping does
Outside the tank · Eggs often survive
A coral dip is a timed bath in a dedicated solution. It knocks pests off the coral so they never reach the display.
Dipping helps against flatworms, nudibranchs, red bugs, copepods, small crustaceans, some parasites, and some algae or bacterial films.
Step-by-step coral dip
Two containers · Blast the crevices
Typical time in the dip is 5–15 minutes — follow the product and the coral type. Incorrect strength can burn tissue.
Prepare dip water
Fill a clean container with aquarium water. Never dip in the display tank.
Add dip solution
Mix to the manufacturer’s instructions. Too strong stresses or damages the coral.
Submerge the coral
The whole piece — tissue, skeleton and frag plug — goes under. 5–15 minutes is typical.
Agitate with a feeder
Gently blast tank water (or the dip) across branches, crevices, the frag plug and the underside. That is where pests hide.
Inspect the container
Watch for pests falling off: tiny worms, moving dots, small crustaceans, nudibranchs. If you see them, the dip is doing its job.
Rinse, then place
Move the coral into a second container of clean aquarium water and rinse well. Then place it in lower light. Discard all dip and rinse water — never add it to the reef.
Pests to look for
Check the plug and crevices · Add photos in the editor
Use a magnifying lens on the underside and the frag plug. Replace the dashed boxes with photos of what you typically see in store.
Flatworms
Thin, often brown or rust-coloured. They sit on tissue and can multiply fast on SPS.
Nudibranchs
Camouflaged on Montipora and similar. Eggs survive most dips — inspect again in a few days.
Red bugs
Tiny red dots on SPS. Hard to see without a lens. Dips help; eggs may remain.
Aiptasia / hydroids
Often on the plug, not the coral. Pick or treat the plug before it goes in.
Vermetids & snails
Tubes and small snails in crevices. Remove what you can before placement.
Algae & film
Some films come off in a dip. Don’t scrape live tissue to get the last bit.
Quarantine
Dips miss eggs · A few days of watching pays off
Separate if you can
A small QT tank or frag rack lets you watch for pests that hatch after the first dip, without risking the display.
Inspect again
Check the coral and plug after a few days. If you find pests, dip again before it goes near other colonies.
Low light first
Even after a perfect dip, start lower than the final PAR and move it up once polyps are out and tissue looks settled.
