Catappa bark tubes have the same effects as Catappa leaves, only significantly stronger. They lower the pH, stimulate the colours of fish, and have a preventive effect against diseases. The advantage of Catappa bark is that the disease-resistant substances are released much more slowly due to the thick bark. The creatures can therefore benefit from it for a very long time (approx. 4 months). Besides these positive qualities, the pieces of bark are also a nice hiding place for shrimps and lobsters.