Hiposalinity issues????

[Midway]

Hi there, i got some fish from the store yesterday (couple of claener wrasse) and I my quanranteen is already in hypo (1.010) cause i already have a fish in there and he's doing fine in hypo. I lowered the salinity on those guys very slowly. I lowered it from 1.028 or close to a 1.010 in something like 5 hours. They looked ok when i finally put them in the tank. This morning one of them was dead and this evenning when i came from work, now the other one is dying. I checked the parameters and everything looks good. This is the first time i treat my fish in hyppo. Am i doing something wrong here?