You can create fluid acrylic paintings using just acrylic paint and water without the need for additives - check out my method here.
Acrylic Paint and Water Method - Creating Fluid Acrylic Paintings
Acrylic Paint and Water Method - Creating Fluid Acrylic Paintings
Acrylic Painting Techniques - 12 Creative Methods
Acrylic or Watercolor Underpainting for Oils
Acrylic Painting Techniques - 12 Creative Methods
The Art of Acrylic Paint Pouring Techniques
The Beginners Guide to Acrylic Pouring
Understanding the Techniques of Pouring Acrylics
How to Paint with Layers - in Acrylic & Oil - Nancy Reyner