please help

[blackhaze266]

I have been monitoring my saltwater tank that I set up yesterday, my salinity tests are all over the charts. Sometimes it is right on, sometimes it is way too high and sometimes way too low. I am not adding or taking away from my tank. It is at a perfect 80 degrees. What am I doing wrong? Please help! Thank you

 

[1979camaro]

what kind of measuring device are you using? sometimes the swing arm hydrometers can get bubbles or salt stuck on them which makes them read eratically