Correct.On that point, at least, you are incorrect.
Carbon dosing (with ethanol/vodka or acetic acid/vinegar) causes no changes in alkalinity that are any different than uptake and use of the same nitro bygen forms (ammonia, nitrite it nitrate) by photosynthetic corals and other organisms.
As alk is depleted when ammonia nitrogen is used as a nitrogen source and vodka dosing does mainly activate rapid heterotrophic growth using ammonia -nitrogen. alk is depleted by vodka dosing. As the nitrification capacity is reduced less alk is consumed by the nitrification process. As photo-autotrops must use nitrate-nitrogen as most ammonia is used up by fast growers alk is increased but at a very slow rate as the growth rate while using nitrate nitrogen is a lot slower. Once the nitrification capacity is removed photo-autotrophic growth may not be able to compenate for the alk consumption.
I do not think it matters much.
No. That concern is not that nitrate may get too low. I assume with any method that you can somehow control it properly. My concern is that causing more nitrate consumption by sulfur will have an even bigger drop in alk than is predicted by the daily accumulation rate of nitrate. For example, lowering nitrate with sulfur will potentially cause less direct consumption of nitrate by photosynthetic organisms. If the daily production is unchanged and the daily incorporation by organisms decreases, that means that more each day is following the sulfur route. Hence my suggestion that the daily accumulation rate is not a perfect measure of how much is consumed by sulfur and thereby, how much the alk is consumed by the sulfur process.
Consuming nitrate by carbon dosing causes no drop in alk, so no such concern exists for it.
It is not the alkalinity wich bothers me in the case of carbon dosing.. Fast growth uses ammonia -nitrogen consuming alk. Once the ammonia is used up fast growers will not be able to compete with other more effective nitrate-nitrogen users. Does carbon dosing actually consumes nitrate? Or is it a nice side effect?
As all processes in a SBNMS take place in a refuge or reactor all processes effecting alk in any way are copensated for before the water enters the main system. This just by providing the substrate needed. How nitrates may get to low? Bad management? Using a SBNMS one can keep the nitrate level at the nitrate level as desired> When using a BADES reactor the SBNMS becomes self regulating at the desired nitrate level. Please inform your selves to avoid useless discussions . All information is available in the Makazi Baharini wiki.