This is not promising to hear about the RedSea Alk test. I just bought the Pro. Unfortunately the only other test available to me is the API. Which I had been using for the last 2+yrs. Decided to switch for comparison reasons only and BRS has chosen the RedSea as one of the more accurate tests available. Our LFS uses only the API
How far off was the RedSea Alk test you preformed? What other test did you compare it to?