Salifert test kits are the top of the line tests for accuracy and precision. Their wide range of available tests have all been designed to detect the smallest traces of certain elements, without interference from other chemicals within the water. These are the best test kits you can buy- hands down. The sharp, contrasting color changes make results easy to read so there's no second guessing. Trust your aquarium to Salifert. Easy to read color change and fast results allows you to effortlessly test your marine water for the correct pH.