Again, I'm not well versed in denitrifiers but I would think the release of co2 through denitirfication would have more of an impact on pH than the absence of O2. Taking a shot in the dark, I'm assuming a denitrifier is a chamber created to cause an anoxic zone for anaerobic bacteria to reduce nitrates to nitrogen and carbon dioxide. If that is the case, it is quite likely that aragonite and zeomag could very well dissolve within this area releasing caco3 and magnesium. If the denitrifier gets the pH as low as 6.7 then it would dissolve the media just the same as a ca reactor except in a calcium reactor you inject co2 to lower the pH. I'd be concerned about the consistency of a denitrifier to continually maintain the appropriate pH for dissolution of aragonite and you may then get varied results in it's ability to consistently release caco3 and mag. You would also then be limited in the effluent rate thus affecting it's ability to maintain appropriate levels within your water column. In all it would seem much easier to dose some mixed up mag flake or Tech M once a week.
I'm not sure why a denitrifier would lower alk levels if the pH inside them is low (must have something to do with the media inside of them utilizing caco3 molecules through the denitrification process). If the pH is low then it would dissolve aragonite thus releasing caco3. This would be an example of that rediculous marketing on aragonite bags actually being true!!! If there is an area that is anoxic, thus creating a zone of low pH through various metabolic processes, then the aragonite media will dissolve releasing caco3 ultimately raising alk levels which would in turn increase pH (even if pH is driven down by co2 levels, increasing alk would ultimately raise pH by increasing it's "potential" low end value). I guess I need to do some more research on denitrifiers to fully understand why it would lower an alk level.
Jeremy
I'm not sure why a denitrifier would lower alk levels if the pH inside them is low (must have something to do with the media inside of them utilizing caco3 molecules through the denitrification process). If the pH is low then it would dissolve aragonite thus releasing caco3. This would be an example of that rediculous marketing on aragonite bags actually being true!!! If there is an area that is anoxic, thus creating a zone of low pH through various metabolic processes, then the aragonite media will dissolve releasing caco3 ultimately raising alk levels which would in turn increase pH (even if pH is driven down by co2 levels, increasing alk would ultimately raise pH by increasing it's "potential" low end value). I guess I need to do some more research on denitrifiers to fully understand why it would lower an alk level.
Jeremy
