Salitnity going from .23 to .25

[milkman]

I have a Refractometer. The salinity has varied from 2 days time. It reads .25 then 2 days later it reads .23 why? I do not have a leak, water level stays constant but can the refractometer change readings due to heat? It has been extremly hot here in So Cal. I just recalabrated the refractometer.

 

[ophiura]

THe only way the specific gravity can truly go down is by adding freshwater (top off, doing a water change). If you added top off water in that time, it might very well go down.

 

[miaheatlvr]

Originally Posted by MilkMan
I have a Refractometer. The salinity has varied from 2 days time. It reads .25 then 2 days later it reads .23 why? I do not have a leak, water level stays constant but can the refractometer change readings due to heat? It has been extremly hot here in So Cal. I just recalabrated the refractometer.
Are you making sure you are cleaning it prior tu use with RO or disitlled water? Yo might have dried salt on your analysis glass that could be affecting you readings.