Add Liquid F/X™ UV water dye for Dramatic water lighting effects. Particle free and fine nozzle/channel waterblock tested. Available in five colors. Highly concentrated with a mix ratio of over 50 to 1 so 1oz will last a long time. Just 1-2 drop per fillup will generally suffice. These are professional grade dyes used in illumination of water for commercial uses and are very bright with even a small amount. The above display shows the illumination under UV light.

 

The yellow/green by nature is the most visual illuminance dye and in the light looks a very flourescent green color.