There are a few things that set the WaterGuru Sense 2 apart from other smart pool monitors and even the Sense S1. The Sense S2 now does 5 test factors – Free Chlorine, pH, Alkalinity, Calcium Hardness, and CYA. It also will monitor the water temperature and the flow of the pool as well.
The Sense S2 is designed to replace your skimmer lid so that there are no floating monitors in the pool, and it stays hidden in your skimmer. New for the Sense S2 is an included floating ring so if you have a spa or lap pool, above-ground pool, or any other body of water without a dedicated standard skimmer lid you can now simply “float” the Sense S2 to get the readings. Note that the pool flow will not be monitored in that case or at least the reading will be very low.
There is also no monthly subscription fee for the device. The C5 cassette lasts up to 4 weeks with one water test per day (although you can do a test on-demand at any time with a press of a button)
Is the WaterGuru accurate? In my testing, it matched up very well against the PoolLab 2.0 and my ColorQ 2x Pro 9 photometer. For various reasons, you will not get the test results to match up exactly except maybe in the lab. Each device takes a water sample from a different part of the pool, even right next to each other you will not get exact results. They also use different technologies to read and determine the results. But within a margin of error the reading all lined up pretty well together.
What I like about the device is that it does not require a monthly or yearly subscription. You just purchase the unit and just order cassette refills when needed, It is also backed by a one-year replacement warranty. 4 “C” batties will also need to be replaced and the app keeps track of the battery life for you. So a very affordable device.
Currently, if you wish to purchase a 3-pack of C5 cassettes you will have to contact WaterGuru directly. They sell a 3-pack with one C5 cassette and two C2 cassettes (chlorine and ph) only. I prefer the C5 cassette for the 5-test factors.