Ägaren till Akvariehobby i Uppsala berättade att när han tog hem rödmunstetror, så skickade leverantören alltid med ketapang som vattenberedningsmedel för dem. Jo, det är mandelblad.

Så här står det på förpackningen:
Ketapang-sea almond (Terminalia catappa) leaves - is a natural multipurpose agent for use in the aquarium.
Characteristics: Effectively improves aquarium water quality, offers bactericidal and fungicidal properties, helps alleviate stress, adds natural tammins to the water, slightly lowers ph and makes water biotope-correct for fishes from softwater, acidic habitats.
Applications:For the preparation of biologically pure water for breeding and keeping ornamental fish, the protection of eggs from infection, and the regeneration of the mycus coating and fins.
Dosage: 1 bag (5g) per 150-200l of water, added directly to the aquarium or filter.
DO NOT USE IN HARD WATER!