With a .1 difference, do you think it’s possible that it’s just the Hanna checker that is giving you a difference in result?
But on a side note, From what I understand, dosing aminos can have an effect on alkalinity, kind of similar as when your dosing bacteria. Aminos add N. When ammonia is converted by nitrifying bacteria, it also uptakes alkalinity. When that nitrifying bacteria is cycled and consumed, that releases that alkalinity back to a degree. When you dose aminos, you are also adding in the nitrates and the bacteria will consume it but you don’t have that initial uptake. But when that bacteria is consumed by processes/coral, that alk is released and can lead to an increase.
Another thing to consider, (if in fact you do actually have an increase and it is not testing error or discrepancy) is the time in which you tested on Sunday in comparison to today. Alk demands change and fluctuate throughout the photoperiod especially.
