refractometer versus hydrometer

ive been using this hydrometer since day 1 and i clean it after each use with vinegar and then ro water. sometimes it sticks and sometimes i just wondered if i was going crazy. id add more salt, hours later the SG would be the same.

anyhow a friend of mine, rubystar, bought a refractometer for her tank. let me borrow it and alas my SG is 1.028!!! verified calibration twice and 1.028 each time. the hydrometer is telling me 1.022-1.023

guess ill be borrowing this often *snicker*

 

yeah they are really worth it and a lot more accurate. i think they r like $34 on ebay...

 

There's no comparison.- Paul

 

BJE

prepare yourself for a shock
if you buy the refractometer , I would be willing to bet that your SG is not exactly what you think it is.

over the years, I have gone FOWLR to reef on 3 seperate occasions and each time I have found that my actual salinity was higher than I believed


Steve

 

I used to use hydrometers but they are so inconsistent and inaccurate!
I bought a refractometer on Ebay and its amazing.
Well worth the $30-$40!!!

 

I have an instant ocean hydrometer. They aren’t accurate, but they are consistent (At least mine is). I got it tested with a refractometer. I found out it reads 2 points high. But it always tests 2 points high. So I know what the salinity really is.

 

So you already know its 2 points off, but what about when it starts being 3 points off or 4? You'll have no idea if it starts doing this. Its just not worth the risk to me. $35 for a refractometer and piece of mind is well worth it.

 

I can only advise you to invest the money and buy a refractometer.... well worth the money. I waited too long to get mine and finally I am sure it is giving me the correct reading!
So, good luck and check ebay. I personally didn't have the time because I had to relocate to Spain, so I paid $99 for mine.

 

If the Seatest swing arm hydrometer is cleaning before checking the calibration, and the hydrometer is cleaned in white vinegar once in a while depending on amount of use, and rinses between uses, the reading will not change.
It is impossible to change other than deposits forming on the swing arm either on the float material, the weight material or both as is usual.
Depending on a refractometer is not the be all and the end all either.
There are problems with variation in the calibration fluids sold, as well as variations in the quality and stability of the refractometers themselves, with some appearing to be pretty constant but others needing constant calibration.
If you calibrate with water, they will not be accurate at the normal reef salinity.
If you want to be that accurate you need to use a conductivity meter or a certified calibrated hydrometer.

 

A refractometer is such a good investment! When I started with my 37 I used a hydrometer, and when I started my 90 I bought a refractometer. The difference in readings between the two was amazing!! My hydrometer was always reading high. I thought my SG was 1.025, but it really was 1.021 or something!!

Definitely get one! I bought mine on Ebay for 30 bucks or something.