LETS START OVER. You need to get a sample of you water and take it to LFS or one of the better sponsor. You need to get your ammonia and nitrates tested but thet should do everything. Also pick of a specific gravity gauge and make sure your SG is at 1.023-1.026. As long as you are in that range you should be good. Test kits can go bad and cheap ones can just not work. Sponsors constintly test water and use newer and better test. Get that done and give us all the parameters. Also how long are you leaving your lights on?
Then if nothing else is looking bad then more than likely your Temp Spike just stressed the shrimp out and they were not able to handle it. I would just make sure that the spike does not have a chance to happen again
