Kachnar Tree Pods
These contain some antimicrobials, flavonoids, and of course, tannins.
Size: approx. 6"-7" in (15.24-17.78cm) length, with a width of about 1/2" (1.27cm).
How To Use: Boil for about 15 mins to help release some tannis. You could also just add them to the aquarium and they will sink and slowly release tannis.
Quantity: Pack of 5