Surprisingly, the natural habitat of many ornamental fish is originally very hostile to life. The water of blackwater rivers such as the Rio Negro in Amazonia is very poor in minerals and very acidly. Many areas of these waters have pH-values below 4. Not a good starting point for the existence of aquatic life forms.
For a long time, it was unclear how discus and other fish, shrimp and other aquatic organisms can exist there successfully at all. In the meantime, it has been scientifically proven that it is the humic substances dissolved in the water that enable survival in such an extreme environment. Humic substances are omnipresent on Earth. But what are humic substances, how do they originate, how do they work and above all, what are the benefits of humic substances in aquaristics?
Most loricariids and many other fish eat aufwuchs. Aufwuchs is a loanword from German language and means something like overgrowth. It describes a conglomeration of herbal and animal organisms which form a living film on stones, rocks, wood, roots and any substrate. It is a species community of algae, bacteria, crustaceans, worms, insect larvae and different microorganisms. This living ensemble is nourishment for many species.
