Long tentacle anemone sudden death?!

[SnowflakeE]

I have a 110g reef that I recently installed a new sump on but had to essentially tear the tank down. I kept my rock in flowing warm water to keep bacterial populations alive. Everything is back in the tank and seems to be doing fine (montis, hammer, zoas, lepto, stylo, etc. pair of percula clowns and a chromis) and until today my anemone. I recently added another LTA maybe it introduced some disease. Anyway, I fed the fish this morning and left for work only to get home to see my 5-6" wide anemone shriveled into a 1" ball on the opposite side of the tank. When I placed it back in the tank about 2 weeks ago it immediately found a spot and dug in.
Params:
calcium: 450
alkalinity: 9.0
mag: 1380
nitrate: 5
phosphate: 0.1
salinity: 35
temp: about 78.0

My guess is this has something to do with a spike because of cycling (maybe pH?) but everything else is fine including the other LTA. Any thoughts, thanks.

 

[SnowflakeE]

This morning the anemone had its mouth tightly shut and was fully open, I also fed it a small silverside 2 days ago.

 

[SnowflakeE]

I also did a water change yesterday. Thanks again!

 

[davocean]

Lots of people have had bad experiences from feeding silversides, myself included, very easily could be your issue.