Indian Almond Leaves or Catappa/Ketappa Leaves are dried all-natural leaves from the Indian Almond Tree, Terminalia catappa which is found throughout much of tropical Southeast Asia. The use of these leaves in aquarium dates back decades to master Betta breeders in Thailand, but in recent years have gained a wider acceptance in home aquariums of all types. They release beneficial tannic and humic acids for animals that inhabit soft, acidic, or “blackwater” environments in the wild. Also known to have natural antimicrobial and antifungal properties, they can aid in healing mild bacterial and fungal infections. Leaf litter along the aquarium’s substrate is a great way to provide an ideal habitat for many benthic aquatic invertebrates and support microfauna populations, and many fish species like dwarf cichlids, small characins, cryptic catfish, and knifefish are specifically adapted to life within this habitat in the wild. In a botanical style aquarium, the leaves act not only as decor and a source of beneficial substances but useful hiding places and habitat for small fish.