Yap,rescape the LR and chg 50% water at the same time,spent me half day to do rescape.Very hard to catch them lucky they hide in 1 pc of LR,I dip the LR on freshwater for 20sec,all claw out less than 20 second and quickly soak back the LR in the old saltwater.The size of pistol is around 1 inch plus.I did not put back all my corals n LS back to tank cos worry no2 shootup,hv to monitor water parameter before putting back the LS to maintank.Hopfully no more pistol in my tank,so far did not hear any click sound last night