I ordered 1 med dog size. I was only needing to treat a 40b plus sump. the large breed dog would treat 300-400g one time. Since the med size was half I felt it would treat 150-200g so I cut it into 3rds and treated. after 12 hours i did a 25% water change and will retreat in 1 week. I can say that the red bugs were gone after the 12 hours. The reason to redose is eggs might not be killed on just one treatment but then again they might.
Make sure you remove any crabs, shrimps, ECT. I missed one hermit and he was dead in 20 mins. Also my corals look much better after just 3 days. I have much better polyp extension already. I am not positive where I got them from but it doesnt really matter. It was an easy fix. I would suggest anyone keeping SPS to have some on hand. Like I said 20$ is cheap but 2 weeks of them eating your corals will drive you crazy wile you wait for it. I was thinking about doing a small group buy on it because if you get 12 month supply for large breed it comes out to like 13$ each