Could the harlies live in a ten? Probably. Would they do much better in a larger/longer tank? In my experience yes, mine are in a 4 ft tank and are always zooming around...
im moving them back now im trying to find a replacement that i can find localy. would the shrimp be ok in a HUGE pickle jar with lots of plants and seeded substrate bc i want the blue pearl shrimp to get their numbers up before i introduce them to the tank where the ghost shrimp may or may not eat some of them.
someone told me that they had a tank of ghost shrimp and they would eat eachother so if they could eat eachother why not smaller versions of themselves?
Who informed you of this? I'm no invert expert but this doesn't sound right to me. I'm sure if a shrimp dies the others will make short work of cleaning up the body, but it doesn't mean they were killed and eaten.