Hi Jessica, do you have a Water Ionizer that produces alkaline water? I had bought what I considered an affordable machine, I never really got the orp that I had hoped for and after a relatively short time the orp began to increase in numbers. The initial readings were around -360 and within a couple of months it was up to -214 or so. I then decided to purchase, what I consider the top of the line machine,it was kind of out of my price range. The same water, with this machine now tests at -760. Some days it is a little higher and some days a little lower, but for the most part very consistant. I've been using the same machine for about three months and the readings haven't changed.