In saltwater tanks deep sand beds (e.g. a 4"-6"+ depth of very fine grain sand either in the main tank or in a remote location such as a sump or refugium) can be used as a form of natural nitrate reduction (as it provides the oxygen-free environment required for anaerobic bacteria to form and convert nitrate).
What are the obstacles that prevent deep sand beds from functioning as a natural nitrate reduction media in a freshwater set up?
What are the obstacles that prevent deep sand beds from functioning as a natural nitrate reduction media in a freshwater set up?