Nested parameters with validations in Rails 4

Question

I am implementing nested forms in Rails 4 using cocoon. I am trying to update the model with nested attributes for other model.

I have request model with nested attributes for filled cartridges:

has_many :filled_cartridges, dependent: :destroy
accepts_nested_attributes_for :filled_cartridges, allow_destroy: true

In my update method for request_controller.rb i have:

.. some code..
@request.update(request_params)
.. some other code ..

Where request_params are defined:

def request_params
  params.require(:request).permit(:name, :address,:description,
     :filled_cartridges_attributes => [:cartridge_name,:client_id,:cartridge_id,		:request_id,:count,:fill_date,:_destroy,:id],
end

The model filled_cartridges has columns:

t.integer  "client_id",                  null: false
t.string   "cartridge_name",             null: false
t.integer  "cartridge_id",               null: false

In my nested form I can delete a field update or add new field as in Railscasts tutorial. When I update one of the field it works, when i delete one of fields it works too. I get an error when try to add new field with some value and hit submit:

SQLite3::ConstraintException: NOT NULL constraint failed: filled_cartridges.client_id:

So it tries to handle nested model too. How to make that the nested models will not be handled at the first time, i need them later, but not at the moment I update my request model.

Note: If I delete my nested strong parameters it will work fine for add and update fields, but it WON'T work for destroying filed, as it requires nested params _destroy and id to be specified.