Sea Monkeys are 20 days old in this video. There are only 3 left from the dozens hatched; two females with egg clusters and one male. My guess is that 3 adults is the capacity of this tiny aquarium. The females are bigger than the male and reddish color. They are now considered adult, fully grown, Sea Monkeys and they will producing either live offspring or eggs called cysts. The females can live up to 3 month.