REFRACTOMETER HELP

flower

flower

Well-Known Member
Okay, I just got my first refractometer. The instructions expalin how to calibrate..the white and blue must be on 0...what it does not explain is what the numbers mean.
One side says 1.030 and the other side says 40 so whats the SG? Is it really that high 1.030? My SG should be at 1.025 according to my hydrometer that bit the dust. I haven't even checked the SH tank yet.
 
1guydude

1guydude

Well-Known Member
It should say...i think some refractometers test more than just salinity...could it be displaying ur sg and salinity....the s.g. is the number one and the salinity is the decimal one! If that helps lol....doesnt ur hydrometer have both too, mine does!
 
flower

flower

Well-Known Member
Quote:
Originally Posted by 1guyDude http:///forum/thread/385830/refractometer-help#post_3385655
It should say...i think some refractometers test more than just salinity...could it be displaying ur sg and salinity....the s.g. is the number one and the salinity is the decimal one! If that helps lol....doesnt ur hydrometer have both too, mine does!
I have a Red Sea hydrometer. It does not have anything but the 1.010 to 1.030 all the numbers are in red except the 1.020 thru 1.023 are in black marked as the safe zone. Now that I'm really looking at it...In the center there are two digit numbers next to black spots, those spots never changed color so I thought until just now it was just decoration. I guess my hydrometer was not so off after all. The highest it can read is 1.030
For some reason my SG is reading 1.030 on both tanks which made me think it was off. But I have the same 1.030 reading from the refractometer. I just added a little RO to bring the SG down.
 
mproctor4

mproctor4

Member
I haven't ever figured out why we would use the numbers on the right side---SG/specific gravity parts per thousand. We just always look at the numbers on the left, salinity. I guess I really should know more about using the refractometer. I will be interested to hear what the experts say. I am not suprised that your hydrometer was that far off. When we first got our hydrometer I had our LFS test it against their refractometer and it was off .03 and got more inaccurate with time. That is why we just went ahead and got a refractometer, unfortunately it was used and came with virtually no instructions.
AAGGHH--looks like we were posting at the same time and your readings weren't that far off.
 
flower

flower

Well-Known Member
Quote:
Originally Posted by mproctor4 http:///forum/thread/385830/refractometer-help#post_3385666
I haven't ever figured out why we would use the numbers on the right side---SG/specific gravity parts per thousand. We just always look at the numbers on the left, salinity. I guess I really should know more about using the refractometer. I will be interested to hear what the experts say. I am not suprised that your hydrometer was that far off. When we first got our hydrometer I had our LFS test it against their refractometer and it was off .03 and got more inaccurate with time. That is why we just went ahead and got a refractometer, unfortunately it was used and came with virtually no instructions.
LOL..I thought my hydrometer was off because it read way up top at 1.030...well the refractometer says 1.030....
even in the SH tank. Well I know the refractometer is near perfect so it does take the guess out of it all. In the end I'm glad to have it, now to slowly bring the SG to normal in the tanks. I asked about what the numbers mean on the right...I hope somebody can tell me soon because such things keep me up at night.
 
slice

slice

Active Member
Quote:
Originally Posted by Flower http:///forum/thread/385830/refractometer-help#post_3385653
Okay, I just got my first refractometer. The instructions expalin how to calibrate..the white and blue must be on 0...what it does not explain is what the numbers mean.
One side says 1.030 and the other side says 40 so whats the SG? Is it really that high 1.030? My SG should be at 1.025 according to my hydrometer that bit the dust. I haven't even checked the SH tank yet.
Well, a specific gravity of 1.030 equates to 39.8ppt salinity, so your refractometer is giving you both flavors. Your specific gravity is 1.030 which is (rounded up) 40ppt salinity
 
1guydude

1guydude

Well-Known Member
Thats wat i was tryin to say LOL
the 38.8 or watever is ur SG and the 1.030 is ur salinity! Does ur new refractometer take the temp into the equation? I forgot wat its called ato or something another...
im looking at getting one soon...
 
slice

slice

Active Member
Quote:
Originally Posted by 1guyDude http:///forum/thread/385830/refractometer-help#post_3385693
Thats wat i was tryin to say LOL
the 38.8 or watever is ur SG and the 1.030 is ur salinity! Does ur new refractometer take the temp into the equation? I forgot wat its called ato or something another...
im looking at getting one soon...
Well actually you have the terms backwards, and I was far too loose with the terminology in the above post, also backwards. Specific Gravity in this case is 1.030, salinity is 40ppt.
 
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