You should not relate need for co2 with nutrients, it's related to light.
We add co2 to allow the plants to process nutrients if the light is strong enough to demand more than what can be dissolved in the water from the atmosphere.
Nutrients will be processed anyways if there is no co2 and the light is strong, but instead of been processed by the plants it will be algae... Starting with GSA IME.
A heavily planted shrimp tank is possible!