A method for determining silver concentration in a solution is disclosed. This method generally comprises immersing a substantially pure, elemental, copper strip in a sample of the solution to be tested, agitating the strip in the sample, removing the strip from the sample, and observing the color change, if any, of the strip. These strips are generally greater than 99% pure copper, and have been coated with a metal ion layer. An alternative embodiment provides for removal of the metal ion layer immediately before testing the silver concentration of the solution. A test kit comprising the active copper strips is also disclosed.