Sorry for bumping the topic. The killer of your shrimp might be water shock, you can use prime, I do it my self no proble
. But the shrimp are very delicate when it comes to water, spike in amonia, nitrates, etc will cause the death of few. Older shrimp are the worst when It comes to adapting to a new tank set up. Why? Because they were already use to the same water for months.
So when you put new shrimps in any tank take your time and place a bit of water from the tank into the bag. LPS should have the same gH, kG and maybe pH, but not the same temperature. water shock is something to watch out for, and if you have a water pump(maybe your tank is to small for one but what ever), put your shrimp(the ones that look weak) in a breeding box or something and put the pump right in front, sometimes a little water flow helps a bit.