WaterGuru Sense S2 Smart Pool Monitor – Digital Pool & Spa Water Tester for Chlorine, pH, CYA & Alkalinity – Wi-Fi Enabled – Includes C5 Cassette, Float Ring & Batteries

It is costly, but it is GREAT to bring up on the phone and see water temp, PH, Alk, Free Chlorine, etc. After entering the Pool Gallons, it also provides recommendation of quantity of chemical to add to bring chemistry into spec. It will provide links to purchase the chemicals from them, but I found purchasing the chemicals from Amazon to be a much better deal. If it eventually fails (hopefully long time from now) I would buy another one.

Worked for about 4 months. Then stopped with daily measurements. Gave manual readings for about a month and now won’t give readings at all. The cassette is supposed to last 30 days but it does not. I have them on automatic shipment and have a bunch of useless cassettes. I consulted the help section and done everything suggested to resolve the issues. For a $400 device it’s absolutely ridiculous. I have contacted customer service, will update review.

I had been one of the earliest pHin users, until Hayward acquired it and then eventually shut it down. I can understand why, since I had received in total 5 warranty replacement units. Then, I decided to go without a monitoring device for one season, which worked fine, until it didn't this year, when I went on a two week international trip and then I returned to a full algae bloom. My gamble that I would be back in time did not pay off, so I got the WaterGuru2 to stop flying blind and Wow! it's so great to have this level of fine grained data. I had been toying with Pentair pH & CL test kits and then the Taylor test kit too, but now I always exactly where my measurements are at. Now I've got a much better handle on all the major variables in my pool, which actually took a while to fully understand since I didn't know any of this before. As you can see from my screen shots, my pH is currently a bit low, but I'm told that's reasonable since I use the Tri-Chlor slow dissolving tablets, but my CYA (CYanuric Acid) is through the roof too high. We figured out today that this is because I had been using 99% DiChlor to shock my pool, which spas like to use, but it's not appropriate for my pool, so I need to switch to 68% Calcium Hypo. I'm also going to see if a new CYA remover does what it says it can do, to get my CYA down to normal levels. I'm also going to add in Green to Clean since my high CYA is preventing the full killing of some nagging algae that still remains and likes to come back. The WaterGuru support team, both Tier 1 and Tier 2 have been a true pleasure to work with. With your purchase of the WaterGuru2, you get two types of Sense2 cartridges, 1 C5, which monitors pH, FC plus CYA, Hardness and total Alkalinity and lasts 30 days, and 2 C2's, which measures just pH and FC daily and these each last for 60 days. Once you get into a steady state C2's are enough. By the way, if you're recovering from something as bad as an algae bloom, please refrain from excessively invoking "Measure" on the WaterGuru2 app, since this will shorten the life of the cassette dramatically, since the measuring film scrolls through the cartridge and it will run out faster. By default the WaterGuru2 measures the water once a day and that's actually good enough for residential owners. Anyone who loves data and is tired of "winging it", or "excessively shocking your pool", or "just paying too much monthly to your pool person" should get a WaterGuru 2.

This looked like an easy, automatic way to track my pool chemistry. In reality, not so much. My CYA only went up 3 ppm according to this unit after adding 1.67 gallons of liquid stabilizer, but my drop kit showed the correct jump. Alkalinity has been off by nearly 30 points compared to manual testing. Free chlorine and PH are sometimes close, but often not. And calcium readings swing even with no chemical changes. The device looks cool and it’s fine if you just want to see whether things are generally going up or down, but you’ll still need a manual drop kit for actual dosing decisions, soooo… there’s that. Was hoping this would really work, but moving back to drop testing to stay accurate

This is a great product, would give 5 stars but you need to understand the measurement you get on a daily basis. Once you look for a trend going on a direction then you make an adjustment. As an example chlorine will be high one day low the next. But over a few days you get the feel of what is really going on. If you don’t like testing with the kits this is worth the cost. But be warned the re-lacement test cartridge are pricey

For the money this is a very good water testing system. I use it to monitor a remote pool and it works well for that purpose. It sits in the skimmer & tests the water daily. You can set the time of day, but no option to skip test days. I think I used two cartridges a season in NorthEast. It tests free chlorine, pH, water temperature & water flow at the skimmer. It has helped immensely, but disappointed it stopped responding after two seasons. Worth the money & relatively inexpensive compared to the few competitors. Cartridge 5-pack is $50. It is accurate & does require wifi to work. They provide water testing for detailed analysis, but my two tests did not get uploaded this season. You can manually upload detailed pool test data if you have a local tester. This house is remote so testing water locally is challenging. The app interface is easy to use & they calculate estimates for what product to add based on pool size. You can have multiple units & share the access to family members. Worth the money, no green pool for two years. Buy long lasting Lithium C batteries, the extended use is well worth the extra cost.

Purchased in July 2025. My experience has been unsatisfactory. Produced many false readings and is unreliable. I removed it after 2 months and went back to using test kit. The only reliable reading was water temp. The idea is nice, but I cannot recommend. Would return for refund, but out of allowed time.