how to use a refractometer...help...

[bigford84]

iv been using a refractometer on my tanks since i started.. almost a year..
but i have just upgraded to a better one. and i dont know how to read this one.. here are some pic..not the best.. of what it looks like on the scale.
the other pic is not my refractometer but looks just like it,with 3 small lines 1 med size line and 3 small lines between 1.020 and 1.030

but my problem is that there is not 10 lines between 1.020 and 1.030. so water from my tank is coming up as 2 lines under 1.030 , so what is that??

and between 1.020 and 1.030 there are small lines and one bigger line about half way between the two.. is that bigger line 1.025???

i have a 55 gal fowlr with 25 gal sump, i want to keep it at 1.025 is that a good idea?? or no?? if 1.025 is a good range to keep it at were is the 1.025 mark on this thing?? thank you in advance.

 

[Kurt_Nelson]

Looking at the photos you provided, I'd say your salinity is about 1.027.

On the SG side, there are five small lines between 1.020 and 1.030 so each line is .002. And you appear to be between 1 and 2 lines below the 1.030 mark... that's why I'm saying 1.027. The big line between 1.020 and 1.030 I'd assume is 1.025.

1.025 to 1.026 is where I keep my tank at, so I don't see a problem with it! Many folks shoot for 35ppt which is about 1.026+... as shown in the nifty diagram below your photos.

[Edit: Just looked at the photos again and noticed that there are five small lines just to the right of the 5 lines I mentioned earlier. Those appear to be staggered in between the other lines, so I'd guess those are your other .002 divisions. In other words, the little lines on the left are even increments of .002 (1.020, 1.022, 1.024, 1.026, 1.028) and the lines on the right are the odd increments of .002 (1.021, 1.023, 1.025, 1.027, 1.029)]

 

[bigford84]

ok i see the even odd idea.. that sounds good, so the bigger line in between 1.020 and 1.030 has got to be 1.025.. nice as that is what im shooting for.. thank you for your help

 

[cmor1701d]

That's correct. The longer line between the tenth marks are the halfway, or 1.0x5 marks.