chicks sneezing

Help! Hi I just noticed today few of my 6 week old chicks sneezing and shaking their heads. Just a clear discharge from nose. I give them first time today apple cider vinegar and garlic in water. They sleep at night time in big cardboard box with heat with shavings at night in a home. Day time...

Video is pretty self explanatory : From a commercial hatchery, seems to be affecting all chicks, they are all less then a week old. Slight clear discharge from nose. Your help is appreciated!