WaterGuru is an excellent addition to any pool. Both the sensor unit and the associated phone app work extremely well and keep you informed on Chlorine, Temperature, and Ph levels on a daily basis, as well as alerting you to problems, suggesting solutions, and maintaining a record of your pool chemistry history. The accuracy is excellent--readings by WaterGuru and by a professional pool store have been almost identical. Not only does WaterGuru save time, but it also allows you to maintain proper pool chemistry levels on a more consistent basis. The upfront cost of Water Guru is very reasonable and replacement cartridges provide 8 weeks of readings for only a few dollars a week. All you need to do is check the app for current information, saving time and effort.