This is something that's got posted on a what's app group I'm in !
Is this how it works as it's above my brain cell capability!
Yes, it can as nitrifying bacteria will use CO2 which they take from CaCO3 and that will deplete alkalinity (as the result is Ca + O and the carbonate no longer exists). However if denitrification is allowed to complete denitrifyers will consume the O2 from NO3 and will release CO2 which then will bind the Calcium and Oxigen to for CaCO3, I.e. Calcium carbonate resulting in an increase of alkalinity. If this happens the typically there is a net 0 in terms of alkalinity shift.
The problem is when the cycle is interrupted by something (e.g. water changes), then alkalinity can go up or down without the dosing of supplements
Is this how it works as it's above my brain cell capability!
Yes, it can as nitrifying bacteria will use CO2 which they take from CaCO3 and that will deplete alkalinity (as the result is Ca + O and the carbonate no longer exists). However if denitrification is allowed to complete denitrifyers will consume the O2 from NO3 and will release CO2 which then will bind the Calcium and Oxigen to for CaCO3, I.e. Calcium carbonate resulting in an increase of alkalinity. If this happens the typically there is a net 0 in terms of alkalinity shift.
The problem is when the cycle is interrupted by something (e.g. water changes), then alkalinity can go up or down without the dosing of supplements