(Salt)How much is too much?

[Secondgen]

I really messed up! Today when I topped off my sump I accidentally added saltwater instead of fresh. My salt shot up to 1.031 from what I thought was 1.026, but I have a hydrometer. When I went to the LFS to have the water tested they showed that the water was actually 1.031. All other parameters were allright. I lost two Tangs a Hippo, and a Atlantic Blue. Is the spike in salinity what killed my tangs? All other inhabitants seem to be fine.

 

[sloshesv]

I keep my tank pretty salty but that is high. See the cheap refractor thread, they're a must.

 

[Secondgen]

As soon as I found out my hydrometer was junk I bought a refractometer off of ebay.