Thank you for the supply.
I don't notice anything in the mouth when I look closely and she has never picked anything off the bottom. It would be very difficult to put the old pump back in but possible, the old pump was is worn out, loud with a poor flow so I figured it was time to upgrade to a newer design. This one the noise is silent with near no vibration so I don't think the running of the pump caused stress.
All I know that morning she ate like a shark then later during the day I added the pump, tubing which need a special tape to make a seal but I read here multiple times that tape is reef safe. I also did run 10 gallons through the pump/tube and there no reviews of people complaining about their fish dying. The tank is well established at 8 years with 75 gallons at the top and a 20 gallon sump at the bottom a mini cycle would be surprising but possible.
My filter setup is a reefer 350 skimmer, a phosphate remover and two bags of cempure blue. The day I changed the pump I did do some filter changes. I changed the chempure and took out the old ones. Amazon was sold out so I bought from a different supplier but they had sold over 1,500 of them and feedback complains.
Since moving the fish from the main main tank to hospital tank slowly been with the changes and lowered the salinity slightly under 1.24.
One emerald out of 3 emerald crabs added was found dead where he was hanging out just now. I can't find the others but my entire tank is overload with over live rocks so its possible they could be alive but I think doubtful. The LFS store told me they had just came in that morning and picked the largest ones which happen to be gray. I definitely don't think it was a molt as slime was coming off the body, clearly dead. With all the water changes and stress already on the crabs hoping in that day at the LFS maybe another water swing finished them off... So far all the large snails are still going strong, corals and the black widow anemone seemed to have split again for 2nd time but it was rather large. Maybe the water changes triggered this.
I took an updated video and this one you can see the fish far more clearly in the hospital tank. Whenever I'm near the tank she basically rests at the bottom but does swim around so that does look a little deceptive but her health does seem to have deteriorated.