refractometer vs hydrometer

[glipper69]

I've been using the deep six hydrometer for years. i've even cleaned it with vinegar and I have been getting a reading of about 1.024 salinity.

I recently bought a refractometer from Marine Depot, calibrated it, then tested my water got a reading of 1.028 (holy smokes thats high) any way I was just curious, those of you that have switched did you notice a drastic difference in readings. because that's no joke.

thanks,
Frank
this is what I used:

 

[inline6]

Did you calibrate the refractometer using distilled water (should be zero?
Did you get a refractometer that compensates for temp?
Salinity should be relatively close.
I would go w/ the refractometer for sure.

 

[marrone]

I was using both the deep six hydrometer and the Istant Oean hydrometer and when I started to use the refractometer I noticed the difference the between them was only offer slightly, .001-.002.

 

[glipper69]

i did calibrate with RO/DI water which I assume would be just as good or better than distilled.

Frank

 

[ECFENCING]

Refractometer is much more accurate. Problem with the cheap swing needle hydrometer is salt deposit and air bubbles.. I got a big difference in reading 1.022 veruse 1.025.

Refractometer IMO is the only way to go.

 

[marrone]

i did calibrate with RO/DI water which I assume would be just as good or better than distilled.

Frank

I use both, RO/DI and distilled water, to calibrate and they're usually the same.

 

[inline6]

Also my instructions say that you should wait 30 seconds to get a reading.

 

[inline6]

Also my instructions say that you should wait 30 seconds to get a reading.

Not sure if that really matters.
I've tried both w/waiting & w/o no difference.
I believe the time is to ensure that micro bubbles are let out.

 

[Pili]

I used the deep six for a while before i got the refracto. When i checked with the refracto vs. the hydrometer, the hydrometer said the SG was about .03 higher than the refracto.

Definatly trust the refractometer, much more accurate.

 

[glipper69]

I did re-calibrate again just to make sure that it wasn't a temp thing, since it was right out of the box from the UPS truck when I initially checked it. after recalibration I did have to make a slight adjustment. But the reading was only slightly better at 1.026-7 (hard to tell). so there definately is still a difference of at least .002-.003. That is incredible, I am pissed I waited so long to get one.

Frank

 

[Pili]

haha, yeah. I felt the same way.

 

[bad coffee]

how was your reef doing before you bought hte refracto?

As long as it's STABLE, it will be okay. most of the animals in your tank won't really care if your sg is a little high. That's as long as it doesn't swing back and forth every time you do a water change.

mine was 1.021. so my salinity was low. but the tank was doing great. so over the next few days I dialed down my litermeter so more water would evaporate. then I did a water change and it's been good ever since.

B