Make sure your water chemistry is good. Phosphates and nitrates are pretty hard on inverts I have found. I have reduced my nitrates to about 20, soon to be even lower after I get my fuge set up. I use PhosGuard to lower my phosphates to about .15. You should drip acclimate them for about an hour and a half to get them used to your water, about 6 to 8 drips per second. I've had a lot of trouble in the past with inverts and by lower my nitrates and phosphates and using the drip method I can now keep them just fine.