Return or itemize within 21 days
After the tenant vacates, you have 21 days to return the unused deposit or mail an itemized statement of deductions plus remaining funds. The clock is not 'about three weeks.' Courts count calendar days from surrender of possession.
Ordinary wear is not a deduction
You may deduct unpaid rent, repairs for damage beyond ordinary wear, and cleaning that returns the unit to the condition at move-in, less wear. Repainting on a normal cycle, or replacing a decade-old carpet that wore out, is usually wear — not tenant damage.
Document as if a judge will read it
Move-in and move-out photos, invoices, and a line-item list beat a single lump-sum 'repairs' line. If you do not have the statement in the mail on time, the statute's remedy is often the whole deposit, not a chance to fix the paperwork later.