Browsing I found this old post. A batch denitrator can be built using an ATO reservoir, a BRS dosing pump, two small power heads and two digital timers you can find at the Home Depot. Total cost close to $275.00 Bacteria strains in our tanks are diverse and many do become a trouble when a carbon source is added directly to the aquarium, causing STN and RTN. When a carbon source is added to a close environment (ATO reservoir) it is used by the bacteria inside the chamber before it makes its way to the main tank. If all carbon source is consumed none will be left for problematic bacteria (Vibrio, etc) development in the coral holobiont. A properly managed batch denitrator does not cause RTN in a RTN susceptible system.
