6 week old coral beauty

[nick05061978]

Hey MR my beauty started flashing and twitching today...i did a 10% change the temp was the same a salinity also was the same. It has been bothering my bicolor blenny and im wondering since ive noticed a bit of its tail is missing will the benny bite it and could this be its stress. Havent seen any spots on it.
Salinity 1.024
Amm 0
Nitrite0
Nitrate0
40 gal with hob refugium and skimmer