OK, no laughing now.

What is put into those tubes to make them all glow in the dark with so many cool colors?

I said no laughing!

[rickss69]

It is not normally the liquid, but the tubing itself that is uv reactive.

[Gutterz]

you can get dye, but it can stain tubes an clear resevoirs Ive read.

[Jeffro64]

Plus dye can clog up the system i've heard... UV would be the way to go.

[Kal-EL]

Dunno if this still works but you can whipe some Tide detergent on your tubing and it'll glow under a UV light.

Thanks for the replies. Glow-in-the-dark tubing, who would'a thought!