What is considered low income

In what context?

in what context    what do you mean

What I mean is there can be different definitions of low income for different purposes. Which of those does your question refer to?

Low income is also someone who receives only minimum wages.

From a CRA point of view, their volunteer tax program is currently oriented toward low income in the 30k-40k range for couples and 25-30k for singles.
Ontario's assistance credit program for renters and property tax payers, Trillium, also uses these levels.

From other perspectives you will probably get other definitions of low income.