Please note that we only prescribe preventive medication per season (Spring or Fall) and not for the entire year.  The reason for this is that oxytetracycline is heat, light and moisture sensitive.  We want to make sure you always have the freshest product so that it is most effective.  Also, colony numbers can change during the season:  loss to swarms, capturing swarms, pests/animal attacks, winter losses, etc.  In order for you to have enough medication to treat your current colonies, we will always prescribe the exact amount of concentrated medication and we do the math to let you know how much icing sugar is needed for the mixture.