So I am very good friends with the owners of my LFS and get about bi monthly water tests on a API Aquaspin that they have for free. I noticed that my alk is always lower on the Aquaspin than my Hanna shows. It showed 7.9 on the Aquaspin, but my Hannah shows 9.0. I dont know if its the transportation of the water in the tubberware to the LFS or if my Hanna is that much off? Has anyone had any experience with this? It's hard to believe that a professional quality tester that costs over $1200 could be off that much, so I wonder if it's me?