Does a spike in nitrates impact alk?

[SaracensRugby]

Was at my LFS the recently and he mentioned that nitrates soak up or consume alk. I had not heard that before, but I just Kalk pasted some mushrooms and my alk dropped by about .33 dkh, and kept dropping. Now I know that is not a lot, but it was running really steady with my trident for a couple weeks, and to my knowledge nothing else has changed. I even dosed about 10ml extra alk and it barely impacted my number (I am only dosing 30ml per day alk). Thoughts?

 

[Randy Holmes-Farley]

Production of nitrate from ammonia consumes alkalinity. If you allow nitrate to rise by 50 ppm this way, 2.3 dKH of alk is depleted.

if the nitrate is stable, there is no ongoing effect.

if the nitrate is taken up by an organism and used, the lost 2.3 dKH of alkalinity exactly comes back.

 

[SaracensRugby]

Thanks @Randy Holmes-Farley. So just so I understand this correctly, since I nuked some mushrooms, and they are wasting away, creating nitrate through the ammonia process, that alk is depleted completely and will not be returned into the system right? Just making sure I am not overdosing now to get my level back to where it was, and causing an overcorrection here soon.

 

[Randy Holmes-Farley]

It will not be returned while nitrate stays steady or if it is removed by water change. It will return if algae or corals use the nitrate.