[i have crabs]

hypo kills ich while its in the egg stage laying in the sand or rocks ,the lower salinity causes them to burst and stops the cycle,so first of all the sg must be at 0.009 or lower because at 0.010 it still can reproduce,so while the ich is still on your fish it has to drop off wich i think can be between 3-7 days and if its in the swimming form thats 3-5 days also,so once the sg is low enough wait a good 3 weeks to be safe then raise it up.