Refractometer reading - is this right?

[westwind77]

I have always used a swing arm to test, but after reading how inacurate they can be from people here I made the move and bought a Refractometer.
So I have 2 swing arms, they both read exactly the same @ 1.023
The Refractometer read @ 1.028 - 1.029
According to the instructions I had to calibrate it 1st, so I took a sample of water from my API tap water filter, put it in a little bag, floated it to same temp of the tank water. Took a sample, let it sit 30 seconds on the unit, then zeroed out the unit. Cleaned and dried the unit. Took a sample of tank water, let it sit for 30 seconds again, took the reading. Those are the results above, which ones should I believe?
The directions say to calibrate with 'distilled water', is that a must? Are my reading being thrown of because of a bad calibration?
House air temp is 70 and water test samples were 79.
I have noticed my snails are not doing the best and some are dying off, could that be because of the high content, if I am to believe the new unit?
Thanks!

 

[locoyo386]

Hi there,
I would calibrate it with distilled water. From what I know refractor's read higher than hydrometer's or should I say it the other way around. This is the error with the hydrometers. I use a hydrometer, but keep my S.G. around 1.023 for that particular reason. Once you calibrate the refractometer, you will get very accurate reading for S.G..

 

[gmann1139]

I would trust the refractometer, but just in case:
How far off was the refractometer when you got it? What did it read before your adjusted the calibration?

 

[florida joe]

Calibrate your refractometer at 68 f