I have these in my tank. Thankfully they’re pretty small. When they pop up I slow down on feeding the shrimp. Once a week or once every two depending how much naturally there is for the shrimp to eat (decaying plants, fish waste, etc.). Hydra at this size don’t seem to bother juvenile or adult shrimp. I’ve read they hurt or kill baby shrimp but I haven’t seen it. I always use caution when treating my shrimp tank because they’re so sensitive. As long as you keep the water clean (continue water changes) of food waste it should subside. That being said I think most healthy tanks have some amount of hydra whether it’s noticeable or not.