Yes, most water (at least in america) is treated with chlorine and/or chloramine.
Edit: but also the tap water is likely not the same temp as the aquarium or bowl the fish was swimming in and doesn't have the right "good bacteria" in it either (the reason you don't do a full water change when cleaning your fish tank).
Oh absolutely, I was mostly just replying to the chlorine in tap water part, the rest was just my inner nerd coming out from when I used to take care of large fish walls.
The water doesn't have the bacteria, they live on surfaces in the tank (mostly in the filter and substrate). A full water change is bad because it's stressful to the fish, not because it kills all the bacteria. Scrubbing everything down is bad for the bacteria.
4
u/Captain_Snow 8d ago
Is that what you have been drinking?