Since 1994, Natural Path / Silver Wings' has manufactured the superior quality and concentration colloidal silver on the market. We offer colloidal silver in strengths of 250 ppm and 500 ppm, which can be diluted to smaller parts per million, such as 10 ppm and 30 ppm . Natural Path / Silver Wings offers the easy to dilute instructions for customers who prefer to take a daily dose of colloidal silver. Many of our customers prefer to take a full strength dose as needed. Our colloidal silver is guaranteed to be a pharmaceutical grade of Mild Silver Protein (99.9% and 0.1% casein), which stays in suspension indefinitely when store properly. NPSW's colloidal silver is made with deoinized water (the water is so ultra pure that it is the same type of water used with dialysis patients). Our colloidal silver is tested for purity and efficacy with in-house lab testing and independent laboratories for micron particle size, parts per million, and particle conductivity. These tests are preformed with every lot number, when it is manufactured, one, two and three years later. A common myth is that all colloidal silvers on the market should be colorless. Many companies that distribute 10 ppm colloidal silver want you to believe colloidal silver is supposed to be clear. However, colloidal silver's color can range from a clear and colorless to a very dark amber color (still clear with a darker amber tint). As a rule, the higher the concentration of colloidal silver, the darker the color of the solution- a dark yellow or brownish amber being the highest quality. Natural Path / Silver Wings 250 ppm and 500 ppm colloidal silver can be diluted to 10 ppm, thus making it colorless.