It's my understanding this applies to shipped fish. OP's fish is from an LFS. Randy had a thread on this a while back. https://www.reef2reef.com/threads/reef-chemistry-question-of-the-day-12.173979/When the bag is sealed CO2 respirated by the fish cannot escape. CO2 lowers ph. When ph is below a certain point the ammonia is not toxic. But as soon as the bag is opened the CO2 is released and the ph comes back up to levels where ammonia is toxic.


