Drip Acclimation of Shipped Fish

LittleMaui · 2026-10-17T13:17:33-0400

I read several "correct" ways to acclimate shipped fish upon arrival. Everybody agrees to float the bag for 15-20 minutes to match the temp, but after than I read different things. I'm curious when ordering online fish (none captive born), after floating the bag - is it best to prepare tank water than matches the salinity of the shipped water, open the bag and move the fish to that water and begin drip acclimation to increase the salinity, OR - do I open the bag and leave the fish in the shipped water and begin the drip acclimation to increase salinity? I find shipped water tends to be around 24ppt (1.0181), which my tank is 34ppt (1.0256).

Scenario one: Adding to display tank
Scenario two: Adding to QT

tbrown · 2026-10-17T13:23:28-0400

I rarely drip acclimate shipped fish or corals. Temperature match for 15-20 minutes, then put them in the tank they're going to. It may not be the most popular but a lot of people do the same.

Decamicron Labs · 2026-10-17T13:26:06-0400

Based on our experiences and calculations, we suggest matching the temperature and then immediately placing the fish immediately into your tank.

The main consideration shouldn't be whether its captive born, but the amount of ammonia that accumulates in a bag. Even if the fish has been starved for a few days, its baseline metabolic rate produces a substantial amount of ammonia relative to the average amount of water in a fish bag. This is counteracted by carbon dioxide which lowers the pH so the ammonia is in the less toxic version, NH4+ and not NH3, so there isn't a big issue at first, but once you expose the water to regular air, CO2 leaves, so pH rises, and the toxic NH3 version of ammonia begins to form.

We ship everything at 30-35ppt.

56longroof · 2026-10-17T15:04:54-0400

Decamicron Labs said:
Based on our experiences and calculations, we suggest matching the temperature and then immediately placing the fish immediately into your tank.

The main consideration shouldn't be whether its captive born, but the amount of ammonia that accumulates in a bag. Even if the fish has been starved for a few days, its baseline metabolic rate produces a substantial amount of ammonia relative to the average amount of water in a fish bag. This is counteracted by carbon dioxide which lowers the pH so the ammonia is in the less toxic version, NH4+ and not NH3, so there isn't a big issue at first, but once you expose the water to regular air, CO2 leaves, so pH rises, and the toxic NH3 version of ammonia begins to form.

We ship everything at 30-35ppt.

Do you think the salinity difference is a issue?

Fish Fan · 2026-10-17T15:05:44-0400

It's not a good idea to drip acclimate fish that have been shipped. Here's Jay Hemdal's guide on acclimation:
https://www.reef2reef.com/ams/acclimation-methods.903/

Good luck!

Fish Fan · 2026-10-17T15:10:23-0400

56longroof said:
Do you think the salinity difference is a issue?

The OP noted that the fish tend to ship in water that's about 24 ppt, and the OP keeps their tank at 34 ppt. Going from 24 ppt to 34 ppt in an instant would be very stressful on the fish.

Personally, I like to QT new fish, and I believe that best practice is to have a QT Tank setup before the fish arrives. I can pull a small amount of water from the shipping bag using an needle and syringe to test for salinity, then match the QT tank to the shipping water's salinity. And then, you can slowly raise the salinity of the QT tank over time.