Need help - Hydra in shrimp tanks

[nacra99]

My CRS tank just got hit by Hydra. I think it probably came through some plants which came with a shrimp shipment.

I recently lost 4 complete batches of shimplets... they just disappeared.. all of them. So i decided to take a closer look and noticed that the tank were full of hydra.

Does anyone know how to get rid of them without killing off the shrimp?

I know flubenol does the trick, but where do you get some in the US?

thanks!