Hydrometer Issues

[rudy63]

In preparing to do hyposalinity in my hospital tank, I purchased a refractometer from this site. Once it arrived, I calibrated the device and went to use it on the tank. However, when I looked through the device, the salinity line was well below the 0 ppm line that was supposed to be the basis.
Does anyone have any ideas as to what I may have done wrong or do I have a defective device?
Thanks to all...

 

[luvmyreef]

Did you try to recalibrate it?

 

[rudy63]

Yeah; I tried twice...both times, the levels came out exactly the same. I didn't have to turn the screw either way both times. I made sure the glass was clean and dry before re-testing too.
Not sure what SWF's return policy is but I'm guessing I'm stuck with it if I got a lemon. :-(

 

[noah's nemo]

I think you mean a refractometer...anyway,what did you use to calibrate it..I got mine from here too awhile back,and its still dead on...

 

[rudy63]

I did mean that...thank you Noah...not sure what I was thinking.
I also purchased the calibrating solution available through SWF.com.

 

[noah's nemo]

something must be wrong then,that solution should be dead on
try distilled water and set it to 0 and run some more tests

 

[acrylic51]

You can use RO/DI water to calibrate your refractometer... No need for the solution. Place the fluid on the lens, close the cover and see what you get. Adjust the line till it reads 0. Recheck it, but really shouldn't need calibrated alot. Are you sure the calibration solution is good?

 

[rudy63]

Thanks for the help everyone...I finally figured it out last night. And, when I say 'I', I really mean my wife since she thought to see if there were any directions on the SWF.com page for the solution. Sure enough, there it was, saying that with the solution purchased, you don't calibrate to 0, you calibrate to 35 ppt. What kind of sense does that make?!? But, after that, I started getting much more anticipated readings for my salinity and sg. I'm amazed that the solution didn't come with any sort of instructions, etc. Maybe it's just me, but that's a pretty big difference between your product and everyone else.
I'll probably go and pick up a small amount of distilled water and calibrate it to 0, just to see if I get the same results...Anyway, thanks to all that commented, if I get different results with the distilled water, I'll let you all know.