You know.... the time while you're treating your tank for ich would be PERFECT for setting up and cycling a brand new shrimp-only tank Then you wouldn't have to worry about ich at all!
Strangely enough I think I might be close to getting permission for a invert only tank. But so far it would only be for if the shrimp overpopulate, which is just as well because I don't have room for another tank in my room so it would have to be in my brothers room and he is currently away from home (college) so I would have to have permission from him as well as from my parents. But I made some modifications to my DIY filter (used to be a DIY carbon filter) to increase water flow and turn it into a bio-filter. The filter is powered like a air powered sponge filter. The DIY bio-filter is currently running on my ten gallon and will hopefully get cycled while running on it. I plan to leave it in for the duration of the ich treatment if not longer. I also plan to do a fishless cycle with this filter in the tank I would use for the invert tank, just to be safe. Again this is only if (more of a "when" if I understand correctly) the shrimp over populate but I am already getting prepared. All I would need to get for the invert tank would be a heater.
But I still plan on starting with my ten gallon being the tank the shrimp go in.