Sea-Monkeys are sold with or without an aquarium. The picture on the left shows an aquarium stuffed with envelopes 1, 2, and 3 inside. The picture on the right shows only a package with envelopes 1, 2, and 3. With the aquarium, the envelopes sell for as little as $14.99. Without the aquarium, the envelops sell for $7.99. The difference is $7. So, to save $7 and get your Sea-Monkey for only $8, one has to provide their own aquarium. This experiment explored the use of 4 different bottles as DIY Sea-Monkey aquariums.