Heres from the gov. site...
Alberta’s tenancy legislation minimizes the impact of rent increases by requiring that six months must pass between increases for monthly tenancies.
The amount of notice required to increase the rent for a month‑to‑month periodic tenancy is three full tenancy months. Rent increase notices have to be in writing, be dated, state the effective date of the increase and be signed by the landlord. If a notice does not comply with these requirements, it is void. Tenants who pay an increase in rent based on a notice that does not comply with the requirements may recover the amount of the increase, with court approval.