I had peppermint shrimp reproducing in my coral tank at my shop in 2012 through 2013.  I had a small survival rate but still was able to sell a few every now and than.  My coral tank was set up more like a refugium with several types of live plants and a huge amount of different types of pods in it.  I never tried to do anything special for them, but again did have a small survival rate.  So I wouldn't be able to answer what kept a few to reach adults, but that being said I'd say it's very possible that some could survive in a tank under right conditions.  They are being tank bred by some company's, but again not sure if they're producing enough to be commercially available on a regular bases.   Best of luck to you that they are peppermint shrimp!