I've recently bred my Pomacea Bridgesii as well! I noticed my two large snails were acting strangely, constantly hanging out above the waterline, then I woke up one morning and found one large egg sac, the next morning there was another, then a few days later, another sac.
I did some reading and read about the two weeks of incubation they need, etc and to provide the sacs with occasional sprays of water if they are in a dry area of the tank. While the lid of my tank does stay relatively moist from the condensation, I provided them with moisture directly from the tank.
After a few weeks, I noticed the sacs had many punctures and there are a bunch of little snails crawling around on my glass! My gosh are they every tiny! They grow quickly, too. :D :D
BTW your shrimp are wonderful, particularly the coloring on Crystal red caridina. From the looks of it the tanks are nicely planted too. I wish I did a live plant setup. :(