I'd trust the Hanna alk because it's not dependent on your eye doing a titration check. But of course make sure you're wiping that cuvette clean with a microfiber cloth before getting the zero and test readings.ALK is dropping despite 15ML/day of AFR. 8.2 from Hanna and 7.2 from RedSea. I dont know who to believe. Calcium is 420-450 and mag is ~1500. Should I get alk/calc/mag test kits from Salifert? I was hoping I would have alk consumption beginning to be dialed in by now but it's looking like it wont be by my vacation.
Any kit is probably going to be +/- 10% depending on age/lot of the reagents so I wouldn't chase numbers too bad, but rather try to hit stability.