Corid, is this the right amount and how long?

[a123andpoof]

My flock has coccidisis and I gave them some corid. I just lost one. The others seem fine, but I noticed my silkies also have bloody poo. I also put them on corid. I found someplace that said 1tsp per gallon does that sound right or do I up the dosage, or lower it. And how long till they all get better?

 

[Judy]

https://www.backyardchickens.com/forum/viewtopic.php?id=368508