Each Froggy’s Lair is a complete aquatic ecosystem, which means you need only change the water every three (3) months and feed the little frogs two (2) times per week. The frogs live anywhere between 2 and 5 years and will not grow any larger than 1.5 to 2 inches in size. The brown sand is actually living sand that manages the ammonia and Ph levels in the water (the most important factor for keeping any aquarium clean and healthy). The plant feeds off of nutrients produced by the living sand and in turn produces oxygen. All of the components work together to make this ecosystem work! The benefit for the customer is that the entire system creates a very low maintenance yet enjoyable aquatic habitat to enjoy for years.