New Chicks...help with small amount Duramycin dosing plz!

I;m new to BYC...I originally posted this in Raising Baby Chicks but was told this section would be better so if you want to just run through my first post on the link below to get a summary of my issue, please go ahead.

https://www.backyardchickens.com/t/...0-to-treat-help-with-dosing-plz#post_11903055

I got my old turtles heat lamp going for the chicks and switched them to the warmest room in the house. I took the chicks outside today and the mostly sick white Ameraucana chick seemed quite energetic. It was 102 today in Dallas so I'm sure they enjoyed the afternoon warmth around 90whatever degrees. Anyway I went to the feed store and talked to them about the chicks behavior, they gave me Duramycin but I'm not sure how much to put in their water. The dosages on the bag are for big amounts of water. I would hate to make so much and then have to throw the water out after 24 hours. Anyone know how to give smaller doses? My 3 chicks are around 3(or 4) - 5 weeks old. Also, I'm wondering if it would be better to just give them duramycin treated water through a syringe separately..? I want to give just a bit to the other chicks since they have been exposed to the mostly sick chick and have tiny sneezes every now and then but not as much as the Ameraucana.