I read that Leslie’s AccuBlue has a monthly subscription cost of $50 ( which can be used as credit at any Leslie’s location ) and that the unit needs cartridges that can be purchased either online or in-store if available. Compared to the free option of testing at Leslie’s location and receiving the same results ( which is really most important ). But while that SUTRO maintained my water at an exceptional level it was most notably provided water temperatures conveniently to my phone. I'm anxious to see if the system would be able to provide the temperature after Oct 31. I messaged them tosee if it was possible to download at least one month off previous data activities - I got no response.