The Office of the Superintendent of Bankruptcy sets limits on what a person or family requires to live. Any income over that limit is called “surplus income”, and as a bankrupt you are required to pay half of your surplus income to the trustee each month.
The trustee sets the amount of payment by taking into account your total income, the standards issued by the Superintendent of Bankruptcy, and your personal and family situation. The Superintendent of Bankruptcy's standards are set out in Directive #11.
You must make all required surplus income payments to receive your discharge from bankruptcy.