I have moderately hard water with a pH of 7.6-7.8 but it will go up during the summer months to nearly 8.0. I keep the tank at room temperature which fluctuates between 75F-78F (during the hottest part of the day). My KH runs around 7dH out of the tap and the tank stays around the same due to the frequent PWC's.
I bought 25 mixed size cherry's about two months ago with plans on having my 10G planted tank as a grow out tank and then moving the larger cherry's to my 20G tropical tank. I never planned on breeding them but a few of the ones I got in were big females carrying eggs and they have all hatched from what I can tell since I now have well over 100 cherry shrimp from little 1/4" to full size 1-1/4"... and still several are carrying eggs.
I moved last month and had to rehome the 20G tank so now I just have my 65G goldfish and 10G cherry tanks. The cherry's can't go in with the goldfish since even at full size, as they would be snacks, which is why I set up the deal with my LFS. I do daily 10% PWC's and weekly 25% PWC's (gravel vacuum, filter maintenance, etc.) since I am feeding several times a day due to all of the shrimpettes swimming around.
Besides their constant foraging and cleaning of the plants and tank, I also feed them a few times a day... a few small pieces (1mm-2mm) of Hikari Algae Wafers (that I use to feed to my Pleco), a few flakes of Nutrafin Max Spirulina Algae Flake Food and Nutrafin Max Tropical or Goldfish Flake Food.
As far as I can tell, I haven't had any shrimp die although I'm sure I must have. I do see occasional shells from molting which are quickly consumed by the shrimp but no actual carcasses as of yet... unless the other shrimp and snails are consuming them before I see them.