Test Kits for Use in Color Testing for Concentration of Certain Contaminant Chemicals in Aquarium Tank Water, Said Kits Comprising a Tubular Transparent Container with Graduations in a Limited Spectral Progression of Colors Keyed to Degrees of Concentration of the Contaminant, and Said Container Containing One or More Vials of Additive Chemicals for Mixture with Specimen Tank Water in Order to Perform the Test