cherry shrimps will do better in a bigger colony. theyre pretty low on bioload so you can put a lot in a small tank. id say start with at least 5 for every 10 gallons to start with. shrimps dont pair up i dont think but the more females is usually a good rule for any breeding. When i had my cherries i just made sure theres a lot of moss for the shrimplets to grow out and hiding areas, temp was in the high 70's, WC weekly, and i didnt need to feed them for them to survive but i did occasionally feed them algae wafers, crab cuisine, shrimp food or just normal sinking fish pellets. when i kept them with ottos they did eat the blanched zucchinis i placed in. shrimplets do make fish food so i would keep them in a species only tank or with nano fishes like celestial pearl danios, male endlers, rasboras, etc. your female guppies might make a snack out of the shrimplets if you dont have enough moss for them to hide in and they will breed a lot more if there were no other fish in the tank with them
theyre pretty hardy for shrimps, but no where as hardy as cichlids, so you should make sure when changing the water to make the new water the same temp as the water in the tank. avoid copper in their diet or tank, and other chemicals that can kill them. they breed readily and you should have a good size colony for feeding within 3 months unless you buy a good size colony.
