refractometer accuracy?

[mwrmma]

so i just got my refractometer on friday and i tested my water with both the swing arm type and the new calibrated refractometer and they read 1.023 and 1.028. so now i am assuming i should go off the refracto and slowly start lowering my SG? i cant believe there would be that big of a difference.

 

[markh30]

I went through the same thing when I first started with sw. I was using the swing arm, which showed a reading of 1.024. When a friend of mine used his refractometer, it showed a reading of 1.029. I don't trust the plastic swing arms. I also found out later on that micro bubbles will influence the reading on a swing arm. These typically form when you add water to a dry unit.

 

[melosu58]

Yes they will show about .05 difference. Mine did the same. Trust the refractometer. Make sure you calibrate it with some RO/DI water.

 

[mwrmma]

thats the first thing i did even though they said it was calibrated when it left the factory. i never trust that saying.

 

[roka64]

Mine was exactly .005 off. my hydro read 1.022 and the refracto read 1.028. I calibrated mine with distilled water. If you are going to lower the salinity, you can lower it quicker than bringing it up. Fish have a harder time adjusting to a higher salinity than adjusting to a lower salinity.

 

[mwrmma]

right now it is at 1.026/7. what do you guys recommend it be at 1.025?

 

[Dr.Nate]

I keep mine at 1.025 but I know folks on here keep theirs at 1.026 or 07 and it's not a problem at all--whichever you prefer.

 

[newfound77951]

It's more important to keep it consistent than to keep it at a specific number. If your critters are happy then a stable 1.027 is fine and better than a fluctuating 1.025.

 

[roka64]

I agree, stability is best. I keep my 55G FOWLR at 1.020 and my 125G (planning a few corals) at 1.025.

 

[melosu58]

what do you guys recommend it be at 1.025?