Sense S2 Smart Cassette - 3 Pack - for WaterGuru Sense S2 Smart Pool Monitoring System

I purchased the unit direct from the manufacturer that's why I'm forced to leave a review under the replacement cartridges I bought on Amazon.I bought this and decided to go test crazy, multiple times a day. We had our reasons, and planned to do so for a bit even though it would come at a cost of replacement cartridges. Being that I'm a bit of a stickler (this is a commercial pool), I also have a Taylor K-2006C test kit. There were times the FC on the Sense 2 was wildly different in tests two hours apart while the FAS-DPD was constant at the same test periods. By and large the tests lined up between the Sense 2 and the old school testing.After a couple of months I woke up one morning and my Waterguru app told me I didn't have any devices connected. I figured somehow the device got disconnected so I needed to reinstall. Tried it, walked through the prompts only to be told the device is registered to someone else. Strange, but technology can be quirky. So I messaged support and 4 days later, still no reply.Seems I have a useless tethered doorstop in my skimmer now.I'm going to stick with the tried an true, my Taylor testing kit.

Product is amazing and saves a ton of time doing this manually. Had a small issue just outside of warranty period, and the company immediately resolved it.

So after my 1st review of the Water Guru C5 test being way of the mark the support group of Water Guru went through the steps on finding the problem. Nothing worked so they sent me a new C5 cassette and now it works great and is spot on the money. So I must have gotten a bad test cassette and they stepped up and sent a new one. Ok a year latter and finding the C-5 cassette is not vary accurate on the calcium hardness. I’m talking way off I’ve had the water tested and it showed a calcium hardness on 350 which is pretty normal for my pool. The Sense 2 C5 comes back with a test of almost 800. Tried all 3 cassettes and results were the same. The Ph and alkalinity were within range as was the chlorine levels. Per water Guru support the calcium hardness test come from a 3rd party manufacturer. Why would they use a 3rd party for their test strips not sure. So I’m going to bail on the C5 cassettes .

First off, the new version of the cassette is only 30 days not 60 days for the same price but you are getting more 5 tests rather than 2. So when I picked up the new sense 2, I ordered a refill. When it came in with only one sense 2 cassette and 2 sense 1 cassettes, I thought there was a mistake, until I realized there is only one 3 pack option where you just get 1 Sense 2 cassette and 2 Sense 1 Cassettes. So I guess the assumption is you only just the Sense 2 cassette for 30 days to balance the pool and then use the Sense 1 for the rest of the season. I wish I had the option for 3 Sense 2 cassettes and not just 1. I think also because they include half the tests of the sense 1. On the WaterGuru website it shows 3 c5 cassettes so I'm not sure if they are changing this or if the Amazon item is different.

I've owned the first version of the WaterGuru sense device for nearly a year and loved it. Occasionally it wouldn't give me any readings for the day but that was easily fixed by removing the cartridge and ensuring everything was clean and then re-running the measurements for the day.Lately I've been having a lot of issues with CYA being way too high. I didn't seem to be getting some straight answers from the store I had my water tested at so I figured I'd upgrade to the WaterGuru Sense 2 device. So I did, and immediately I've had issues. Apparently there is a known problem with the S2 cassettes where the CYA (stabilizer) isn't measured accurately. By accurately I mean it either doesn't measure CYA or it just measures it as 0. Luckily I had ordered a 3 pack of S2 cassettes (or so I thought) and replaced the cartridge. I finally got a reading and it was super high (no surprise).The problem that I have is that the title says it's a 3 pack of cartridges for the S2 device which is true. But what they don't tell here is that it's 1x C5 cartridge (which measures everything) and 2x C2 cartridges (which only measure chlorine and ph). The two C2 cartridges have been upgraded from the S1 device to last 60 days each (from 30). So this means out of a three pack of cartridges I have 150 days of tests but only 30 of them measure everything the Sense S2 claims to measure.There is no way to not go 3 months without testing CYA and the others. Because if I do C5 (30 days) then 2x C2 (120 days total) then that's three months on the right. If I do C2 then C5 then C2 that seems like it would work until I get to the next round which would then be C2, C5, C2. So we're back to a 3 month gap.This is absolutely useless. I want all the cartridges to be C5 so that I can measure everything daily. I absolutely do not want any C2 cartridges which is the whole reason I upgraded to the Sense S2 device. Not to mention the CYA is a known issue and I've already had to throw away one of the C5 cartridges.The whole point of this device is to measure the pool chemicals myself on a daily basis but WaterGuru has decided to make that completely ambiguous. Had I realized this, I wouldn't have bought the Sense S2 device or these cartridges. With the way the cassette packs are sold, in one years time frame, I would only get results for all the measurements 60 days out of a full year. The rest of the year would be the same results as that from the Sense S1 device. That's completely unacceptable and I have no idea how they justify this to customers.----- Edit 09/25/2023 -----Updated from 1 star to 4 stars.I had complained to WaterGuru about the issues I was having shortly after writing this review and they definitely made an attempt to make it right. They sent me 3 free C5 cartridges shortly after writing this review. Mainly because my first C5 cartridge wasn't measuring stabilizer at all and because I was considering returning the device and going back to my first generation WaterGuru device.After several months, I can say the device has been working very well. The cartridge definitely seems to be a lot better and reading measurements much better. I also received a call from WaterGuru today informing me that the supply chain issues are gone and they're now offering 3 full C5 cartridges in the pack instead of 1 C5 and 2 C2 which is honestly amazing. I live in Florida and have a pool heater so I'm able to use my pool year round so monitoring stabilizer is critical. I hate having to drain my pool and re-add water when it's just easy to monitor the CYA and add liquid chlorine when the tablets aren't performing well. The sun and heat during the summer absolutely zap the chlorine levels but leave CYA untouched. So monitoring this piece was the only thing missing from my original WaterGuru device.In the end, I do absolutely love the device. It takes all the guess work out of maintaining the pool. I check it once in the morning, add whatever chemicals are needed, and move on. I rarely even use manual test strips and only take my water sample to be tested about every 2-3 months (vs every month when I didn't have WaterGuru).As for the accuracy, it's really close. Of course no test strip is ever going to be as accurate as a chemical test that you get at a pool store but it's so close it's not even worth worrying over. Sure, you could use a manual test strip and there might be a difference but first, it's negligible, and two it's not even certain which is more accurate. Just because there might be a difference doesn't make WaterGuru wrong. Heck, even both could be correct but instead it's the person reading it or the lighting conditions that make it look different than it really is. At least with the WaterGuru device you get consistent readings because it uses a test strip in an isolated environment with its own light and sensors to read the strips. This at least ensures it's reading under the exact same conditions each time.You could argue that it's off just a bit with a real test from something like Taylor but honestly it won't matter. If you only use the WaterGuru and follow its advice, your water will absolutely be clean and you'll be able to swim anytime you want without any hesitation. It literally takes the guess work out of it which is what it's designed for. Or, you could just go to the pool store and have it tested and listen to whatever bad advice they give you (which they often do depending on who is there). Honestly, just do it yourself based on the advice from WaterGuru and you'll have a perfect swimming pool all the time. And trust me, that's coming from someone whose pool is surrounded by a large lake and canal and easily gets algae blooms. WaterGuru is more than enough to keep all of this at bay all by itself. Every quarter or so, go get the water tested for phosphates and that's all you need. So easy.