It would be best if you could weigh them and dose them as accurately as possible. But yes, the treatment is five consecutive days.For gapeworm I have to give them 0.75 ML of Safeguard for 5 days and that's it? They're probably around 3 pounds.
Since gapeworms are rare in chickens, if you have more than one that is sick, it's probably a respiratory infectiontion, not gapeworms.