Unfortunately, it is true. He is a direct quote from "The Marine Aquarium Problem Solver" by Nick Dakin- "What should be done if poison [from the puffer] is introduced into the aquarium? -Remove all inhabitants and place in another vessel or vacant aquarium, and perform a 100% water change; install fresh activated carbon. Toxins take effect quickly, so aquarists must be swift to prevent total fish loss."
Kinda scary huh?
-Mark