This cool new bioluminescent bioball is a handmade glass ball filled with ocean water and living marine algae called methanogens, a mixture of marine methanogens that produces bioluminescence. These algae glow when they are stirred. They are very common in tropical waters. Each single algae culture has about 100 ml. This culture requires a high level of light, 200 to 400 foot-candles, 18-24 inches from the culture, 12 hour cycle. It makes a great gift, especially for those who are afraid of the dark.