Are you topping it off with freshwater on a regular basis?
I'm not exactly sure what you mean by testing the left side, the right side and the middle though, being that it's all one body of water.
Yes, make sure your not getting any bubbles sticking to the arm. IMO swingarms are good for a quick check to see if your in the ballpark. At some point you may want to look into getting a refractometer for consistency in your salt mixing and overall salinity. Just my 2 cents worth.
I mixed salt in water in a 5 gal bucket then poured it in. I just measured again andthey're getting closing now but it measures 1.022 1.023 and 1.023. I measure with a fluval sea hydrometer
Or a glass hydrometer .. Yes i am OLD... i cant help myself
I just checked again and the farther I am from the filter the higher the salinity and thanks everyone for the responses
I've had my hydrometer suction cupped to the inside of my tank in the middle and 1.019. What should I do to get my level up? Just pour salt in the tank or mix outside the tank and pour in