
They work great. I've had another set for about 5 years and haven't stored it in solution as recommended. Here I think I'll give it a try had a pH problem in my reef tank and decided to buy a new one.I have a matching Milwaukee pH monitor which I think served me well with the old sensor.The old sensor read 7.8 consistently and I just calibrated it before one.So after calibrating it with a solution of Ph 4.0 and Ph 7.01 and :7.8 I installed a new one so seems like they are lasting longer than the manufacturer The reason I'm not giving it 5 stars has to do with the fact that it consistently reads somewhere between 0.1 and 0.4 outside of the expected range compared to friends' high-end meter sure be made sure that the aquarium is within the range (which is possible to vary t sure 0.5 is good. But next time I would control it better. If you keep an aquarium this should be fine. But if you are using for more important or health related things I would go elsewhere. Hope that helps.

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