I have been using the Sense product for 4 years and, overall, I’ve found it to be accurate—on par with any other company I’ve tried. The first model of Sense only tested for pH and FC, but the latest model also tests for CYA, TA, and CH, which is very convenient. What I truly appreciate about this company is their excellent customer service and the way they stand behind their product. Over the four years of use, I’ve had to replace the unit three times, and each time, the company quickly addressed the issue. They conducted a test on their end, identified the malfunction, and immediately sent a replacement. Most recently, instead of replacing my old model, they sent me the newest version, and I absolutely love it. I no longer need to run separate tests for calcium hardness, total alkalinity, or stabilizer—the unit handles all of that. I have a saltwater pool, and the unit works perfectly with it. The skimmer is located about 30 feet from my house, and I have no trouble connecting it to the internet