I'm not sure then. Maybe some of the experts here will have better ideas.
It still seems impossible to cycle a tank with shrimp in a week. Ive never used that method, but have never heard of it cycling that quickly. With the bottled bacteria (which is what I used), it would be a week, but that needs an ammonia source to cycle properly, which means either adding a fish or additives.
My gut tells me that it was ammonia and trites that burned the gils which is causing the weird behavior. My only other thought is that the tap water has something in it or maybe your salinity is off? What is that ?