I dont treat. I go back and forth about it. If I were to treat I would use one of the organic acids. I am trying to do a Fall feeding with honey and herbs to boost immune and antiviral properties. From my current understanding it is disease and virus that really effect the bees. I feel to many people are looking for a 'silver bullet' approach to it. Also feeding sugar changes the digestive track to a pH of 7 instead of around a 5. Big difference and it allows virus's to flourish.