Clean container
A bucket or tub used only for aquarium water, large enough for the final volume shown in your plan.
Free livestock acclimation tool
Fish Acclimation Timer & Drip Rate Calculator
This free calculator tells you how long to drip acclimate new fish, invertebrates, or corals, how fast to set the drip in drops per second, and when the water in your container has doubled. A built-in timer walks you from floating the bag to netting the animal into your tank.
Drops per secondSalinity gap awareVolume milestonesBuilt-in timer
New arrival
Tell us about the bag
Clownfish, damsels, gobies, blennies, chromis
A typical fish bag holds 1 to 2 cups.
Drip line drop size
Airline tubing drips run about 20 drops per mL. Count drops for 15 seconds into a measuring spoon to calibrate yours.
Your drip plan
Hardy fish: 45 min total
Drip rate
2.6
drops / sec
Flow
7.9
mL / min · 158 drops/min
Drip time
30 min
after 15 min float
Final volume
473 mL
use a 750 mL+ container
Add 1 cups (237 mL) of tank water so the bag water is diluted to 50%. No drip line? Pour in 39 mL every 5 minutes (6 times).
Salinity moves from 1.025 to about 1.025 before the animal goes into your 1.025 tank.
Hardy fish tolerate a moderate drip. Keep lights dim for the first few hours in the tank.
Acclimation timer
Ready when you are
00:00
15:00 left of floating. Next: 473 mL in the container at 45 min.
Keep this tab open. A tone plays when it's time to start dripping and when you're done.
Step by step
- 1
Float the sealed bag 0 min to 15 min
Float the unopened bag in the tank or sump with the lights dimmed for 15 minutes so the water temperature matches.
- 2
Drip tank water into the container 15 min to 45 min
Pour the bag water and animal into a clean container and drip about 2.6 drops per second until the water reaches 473 mL.
- 3
Net the animal into the tank at 45 min
Move the animal with a net or a cup of its own water, then throw away the container water. Never pour bag water into your tank.
Volume milestones
| Timer | Water in container | Bag water | Salinity |
|---|---|---|---|
| 15 min | 237 mL | 100% | 1.025 |
| 45 min | 473 mL | 50% | 1.025 |
Add new arrivals to your livestock list and track water tests after every addition in My Reef Log.Start tracking free
What you need to drip acclimate
Airline tubing
A few feet of tubing with a loose knot or a small valve to control the drip from the tank to the container.
Net or small cup
To move the animal without adding container water to your tank. Keep starfish submerged in a cup.
How the drip rate is calculated
Each animal type starts with a drip time and a number of volume doublings. The calculator adds 15 minutes for every 0.001 of salinity gap beyond 0.002 and adds doublings until the jump left at transfer is 0.001 or less. Water to add is the bag volume times 2, 4, or 8, minus the bag water; divide by drip time for mL per minute, then multiply by drops per mL for the drip rate.
Drip acclimation vs. floating
Floating the sealed bag only matches temperature. Dripping slowly blends in your tank's salinity, pH, and alkalinity so the animal isn't shocked. Hardy fish can be float-and-cup acclimated with the five-minute pours in your plan; invertebrates should always be dripped.
How to use the acclimation calculator
Step 1
Describe the arrival
Pick the type of livestock, enter how much water is in the bag, and choose how long it was in transit.
Step 2
Add salinity if you can
Enter the bag and tank salinity in SG or ppt so the calculator can extend the drip for a gap.
Step 3
Float, then drip
Float the sealed bag, then empty it into a container and set the drip to the calculated drops per second.
Step 4
Use the timer and transfer
Start the timer, watch the volume milestones, then net the animal into the tank and discard the water.
Fish acclimation FAQ
How long should I drip acclimate a fish?
Most saltwater fish need 30 to 60 minutes of drip acclimation after a 15-minute float to match temperature. Hardy fish like clownfish do well with about 30 minutes; sensitive fish like tangs and wrasses do better with 45 to 90 minutes. Add time if the store's salinity is lower than your tank's.
What drip rate should I use for acclimation?
A common target is 2 to 4 drops per second from airline tubing, which is roughly 6 to 12 mL per minute. The right rate depends on how much water is in the bag and how long you drip: the goal is to double the water volume at least once, and two or three times for invertebrates.
Do invertebrates need longer acclimation than fish?
Yes. Shrimp, crabs, snails, starfish, and urchins can't adjust to salinity changes as well as fish, so they need a slower drip of 60 to 180 minutes. Starfish should stay submerged the whole time and never be lifted into the air.
Should I acclimate overnight-shipped fish for longer?
Usually not. During long shipping, ammonia builds up in the bag while the low pH keeps it mostly harmless. Adding tank water raises the pH and makes that ammonia toxic, so overnight-shipped fish are best dripped for about 30 minutes or less once the bag is opened.
Can I pour the bag water into my aquarium?
No. Bag water can carry ammonia, medications, parasites, and waste from the store. Net the animal or move it in a small cup, then throw away the bag and container water.
Related tools
Quarantine Tank Planner
Size and set up a quarantine tank for new fish before they reach your display.
Reef Fish Compatibility Checker
Check that a new fish will get along with your current livestock.
Fish Tank Stocking Calculator
See how a new arrival affects your tank's bioload.
Salt Mix Calculator
Mix new saltwater to the right salinity for water changes.