A landlord can only deduct money from the security deposit to cover the cost of any repairs for damages done to the apartment or rental house that was done by the tenant and not a cause of normal wear and tear.
For cleaning the landlord can only deduct from the deposit for filth that is excessive and not just a little dirty.
If you leave the apartment or rental house and have done damage to it or left the rental house or apartment really dirty then the landlord can deduct part or all the money from the security deposit to cover the cleaning and repairs needed to get the apartment or rental house back into a livable state so they can rent it out to a new tenant.
The landlord should put it in writing of any damages you've done or how dirty you've left the place and should also have pictures of the place in case you or they go to court.