Wood and bark

Wood and bark both contain many good substances (tannins) that help prevent diseases and bacteria. In addition, wood and bark is used by shrimp to graze for microorganisms. This makes driftwood and bark ideal to use in the aquarium.
 
It is important to never boil the driftwood or bark. The treatment with hot water will destroy the wood structure, this will later cause the wood to rot in the aquarium.