Wow!! I just looked up the prices of the Marine PinPoint digital testers.....I major sticker shock! The pH test alone was $70! I think I'll stick to my API tests for now. I have a Seachem test for pH and Alkalinity (which I don't test yet), and then a set of API tests for pH, ammonia, nitrite, nitrate. I like to use the both the Seachem and API test when I'm testing my pH. In general, they've both always had the same results. When I run out of API, I'll purchase Seachem next since that seems to be highly recommended.