[Zbrafish] How to get rid of bleach after treating zebrafish facility!

[Vishal]

Hi there,
I am wondering what is the best way to get rid of bleach if we bleach
our fish facility? would keeping the drain completely open for several
days or 1 week flush away all bleach from the system? I would like to
have your suggestions for this matter. I would really appreciate your
all help.
Many thanks in advance,
Best regards,
Vishal