In article , says...
Am I supposed to leave my goldfish in the tank while gravel vacuuming?
I thought I had to move them to a separate conatiner with some of the original water, temporarily.

Which ever ever method stresses the fish less. I never removed mine,
but they're used to me sticking my arms and tubes and stuff in
there. Netting or hand-catching them to move them someplace,
then doing it all again for the return trip would be harder on them
than just getting used to the process. OTOH, some fish are
really freaked by their first few water changes,
especially in smaller tanks where there's no place to hide.
Your call in that case.

I say let them stay and just be careful with the tube.