I asked my husband to add the vitamin liquid to the chickens water. A couple days later I noticed there was a tinge to the water, caused from the vitamins, so I asked him how much did her give. He told me a cap full. Well the directions say 15 ml to 100 chickens. Well I have 20 chickens, and the main watering can holds 30 liters of water. I would imagine that a cap full is about 50 ml. So my 20 chickens should get a total of 3 ml a day. So now I have to figure out how much they drink a day. Does 2 liters sound like enough? These last 2 days have shown a marked decrease in egg production. I was wondering if the vitamins could play a part in this.