I’ve been using api to test my dKH since the beginning. Also using instant ocean reef salt for several months until this week, I bought redsea blue bucket. I just got my Hanna dKH tester. Hanna output the result at 6.5 dKH twice, while API shows range around 8dKH. Not sure who to trust! What do ya think? I mixed a gallon of fresh saltwater. Tested the dKH to see if the Hanna is accurate. It gave me a result of exactly 7.0 dKH twice. I’m thinking about getting another type of test kit lol
