Grow expanding gel like cubes. 100 cubes supplied.
Super absorbent polymers absorb large volumes of water when placed in water and are turned into hydro gels.
The volume change can be an incredible 250x of the original volume and is fully reversible.
The gelled polymer contains up to 98% water so it has the same optical density as water and becomes invisible in water.
Can be coloured by added food dye.