Review on Hanna Instruments Marine Calcium Checker by Brenda Black

It's a Hanna tester for starters, so it couldn't be simpler. Not sure how others like BRS have found it so difficult to get accurate readings from this as I double check the Red Sea kit every time I use it. I'm within 10ppm of the approximate reading which I can check against the dkh and PH readings to see if they seem reasonable and accurate. They do. For example one day I got a reading of 360 and checked the pH and it dropped to 7.83 and the dkh to 7.4. So exactly in line with what I expect them to be based on 360 degree measurements when I normally use 430ish-9.8 and 8.2 respectively. Review and run other tests as well to ensure they are within reasonable bounds of what Hanna is saying. I think one passage confuses many and leads to inaccuracies. You fill up with 1ml of solution, then fill up to the 10ml mark with Rhodi. I have a feeling a lot of people put 10ml Rhodi on top which is 1ml too much and the sample will debut 10% more than it should be. I also use a label on the vial similar to how API kits are meant to be used, with the top of the vial on the line and the vial sticking out from just below. Imop is how it should be used. When I tried measuring with a syringe several times, I got readings that were far from what I expected, and they were confirmed to be wrong on other tests. Maybe the syringes are off, maybe the human droppers are off? I do not know. But with good eyes and using and using API tests for certain things, fresh and salty, I get readings at 10-15ppm from what other tests should be, and what the dk and ph levels are.