Tylan 50 in water???
Tylan 50 is meant to be used by injection, but many use it orally. I would just give each of them 1/2 ml or cc twice a day for 5 days. Give 1cc if they are over 5 pounds. There really isn't enough in the vial to treat the water. I also would not treat chickens who aren't showing symptoms, but you should separate those who are being treated. If you find the Tylan Soluble Powder, which is also available online, the dosage is 1 teasoonful per gallon for 3-5 days.
Edited by Eggcessive - 2/14/16 at 4:10pm