To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyses reviews to verify trustworthiness.
Results tend to be close to what I get from liquid tests, with the exception of nitrates (always higher on liquid tests). Results are also pretty consistent. Color-matching is not too difficult, but I sometimes have trouble with the general hardness scale. Overall, a good time saver, but I would still recommend testing with liquid once in a while.
Arrived fairly quickly, have a good long date on the package. I use these all the time and like them, find them to be more than accurate enough for any aquarium needs. Much better price in this quantity than in the smaller packs in retail stores.