Vitamins Plus -In addition to the usual vitamins and electrolytes, GQF -Vitamins Plus contains organic acidifiers, and a supplemental source of live naturally-occurring microorganisms, such as: Lactobacillus, acidophilus and Enterococcus francium. Mildly acidifies drinking water, lowering pH, Supplements gut acid production which is often low in immature birds. When To Use GQF -Vitamins Plus -Chicks -First seven days after hatch then one day per week there after. Also, after moving birds and during extreme weather. Breeders -As a supplemental source of nutrients during extreme weather, when there has been reduced feed intake. All Species -Use for 3 to 5 days as needed.