Faulty Hydrometer?

[prodogg02]

i almost killed every thing in my tank due to a bad hydrometer,had a salt level of 1.029,talked my lfs owner in to selling me a refractometer for 1/2 price,the crapy part was it took me adding a cleaner shrimp 27 bucks and a sand siffter star 20 bucks to find something was wrong when they died in like 1 hour.