My Lava Lights, 3 out of 5

I've been playing around with Lava Lights for about 5 years now. Only one of these is a true "Lava Lamp", it is the one on the right (15" Tall) with clear water and Cobalt Blue Wax. The other two, I don't know who made them. The Red one (18" Tall) has clear water and Red Wax. The one on the left (31.5" Tall) is my biggest, it has clear water and Yellow Wax.