What is the difference between Vallejo thinner and flow improver

So do I need to mix any thinner to air brush paints? I tried mixing these two colors, but it was a little thick and wouldn't spray : r/minipainting

What Is The Difference Between Vallejo Thinner And Flow

Vallejo Thinner, 32ml : Arts, Crafts & Sewing

Vallejo – Metal Colours - (Singles all colours, Full Range) 32ml Bottles

Vallejo Auxiliaries - Airbrush Flow Improver

Primer Problems

Replacement Model Master Acrylic Thinner? - General Painting - KitMaker Network

Review: 6 Acrylic Mediums ranked (incl. Contrast, Lahmian, and Speedpaint Medium) » Tale of Painters

Anyone know what's the cause of this. I thinned it using Vallejo thinner plus a couple drops of flow improver. It just beaded up like oil on water or it pooled up