Never done it myself but I believe you drop the pH. Pending on what your pH is just use RO and do WC everyday or every other day. I think this is suppost to mimic the rainny season. I know some dont need this and they'll just breed when they feel like it, like some at my lfs.
If I read your post correctly you have 2" geos? If so you will have to wait awhile cuz they are still babies. Also like posted above they'll pair off.