I would say it is best to make your own. I just made 16 ounces of 20 ppm with my silver puppy on Auto mode. The color is usually clear or light yellow. If it is more yellow it is less ionic. Clear means smaller ionic particles. Some say Clear is best some say yellow. My Silver solution works better than any $30 per 4 ounce Silver I have tried before. I can use the coloidal silver in many ways and even give it away as it now costs very little.