Refractometer for poor people

[N1Husker]

I see super expensive refractometers all over the place. So, simple question, why not just buy this one?

Amazon.com: Salinity Refractometer, Aquarium & Seawater - Dual Scale (1.0 to 1.070 S.G.): Pet Supplies

I've been wanting to pick one up, just haven't been able to spend too much money. The one in the link reviewed really well, but the price just seems too good to be true, so I wanted to see if you guys had any opinions. Thanks!

I was checking out the refractometer that BRS has for sale on their website and it is the same one that is being offered from Amazon, it's an ATC, but the one on Amazon doesn't include the calibration fluid, but is the same tool. It's the one I have and I love it.

 

[Thrawn]

Got it today! Just tested it. My tank was .002 higher in SG than I thought it was lol is it bad that I'm excited to test my salinity now?

Sent from my DROID RAZR using Tapatalk 2

 

[HUNTER01975]

Got it today! Just tested it. My tank was .002 higher in SG than I thought it was lol is it bad that I'm excited to test my salinity now?

Sent from my DROID RAZR using Tapatalk 2

NO WAY i feel the same way about using mine.. feel all smart and fancy...lol

 

[N1Husker]

NO WAY i feel the same way about using mine.. feel all smart and fancy...lol

Yeah, kind of like a scientist or something. When I test my water my wife says I look like a scientist with all of the test tubes and everything.

 

[dnjan]

Hydrometer = cheap refractometer

Only until you break it ...

 

[Eileen60]

Hydrometers are less accurate and as a result less reliable.

 

[dnjan]

Hydrometers are less accurate and as a result less reliable.

Actually, it is hard to beat the accuracy of a quality hydrometer unless you are spending around 10 times the hydrometer cost on a refractometer.
However, cheap hydrometers are a total waste.

 

[Arenzael]

I got my Refractometer from eBay for $24.
Forgot to get the calibration fluid when I first bought it though.

 

[senji]

to accureatly use a hydrometer u need to have the temp altitude conversion charts. mojo told me this once.

 

[DTECH07]

to accureatly use a hydrometer u need to have the temp altitude conversion charts. mojo told me this once.

+1 The Salinity will vary according to the waters temperature.

 

[dnjan]

+1 The Salinity will vary according to the waters temperature.

the salinity or the specific gravity?

Within a reasonable distance from 60F (typical calibration temperature for many hydrometers), the correction is .001 per 10 degrees F.
So if your water is 80F, add .002 to the hydrometer SG reading. So for the precision needed for aquariums, a hydrometer is a very precise solution, with no need for calibration fluids.
If only the darn things didn't roll off the table and break so easily ...

 

[DTECH07]

Salinity (as you say) is the measurement of how much salt is dissolved in the water. In marine conditions it tends to be about 35 grams per litre, which also tends to be roughly 35ppt.

Specific Gravity relates the weight of something. We refer to the specific gravity of sea water as to how it is different from pure water at sea level. Pure water woul dhave a weight of 1 (identical to itself). Sea water tends to have a Specific Gravity of about 1.025, that is it weighs 1.025 times as much as the similar volume of pure water would. SG is temperature dependant, and a hydrometer will red slightly differently as teh temperature increases (how much depends on the salinity of the water).

Also, when using a refractometer you are actual measuring the refractive index of the water, which is converted using the scales on it to give you the salinity or SG.

 

[dnjan]

Since seawater refractometers are normally calibrated to sodium chloride solutions (not actual seawater), how large is the error? I remember stumbling across an article on that topic years ago, but don't remember where.

 

[DTECH07]

if a refractometer has a deviation or margin of error of 1% per .001, that means that if you calibrate it to 1.000 with distilled water, that reading 1.025 might be as much as 25% off. Granted, this is a highly exaggerated situation for the purposes of explanation.

Therefore, what you want to do is calibrate the device using a reading that is as close to what you will usually be reading with the device, so if you are usually reading 1.025, then you should calibrate with a 1.025 solution, so if you read water that is 1.024, even with the ridiculous margin of error described above, you will only be 1% off at most

reefkeeping.com/issues/2004-06/rhf/index.php

 

[HUNTER01975]

dtech07 thanks for that link there was lots of good info in there.. some of it lost me a little. But I believe I understand most of it..

 

[DTECH07]

NP but I know that as we ask questions as you have and get the multiple examples as replies to those question we start to see in great details the inner workings of environment we are maintaining and how to get the maxium and balanced results. Ok that was wordy we need in short RIF (Reading is Fundamental). Haha

 

[HUNTER01975]

NP but I know that as we ask questions as you have and get the multiple examples as replies to those question we start to see in great details the inner workings of environment we are maintaining and how to get the maxium and balanced results. Ok that was wordy we need in short RIF (Reading is Fundamental). Haha

It has been truly mind blowing all the different stuff there is to learn.. and how on most day I log in here and find something new to learn. Some times this place is alot like church you just have to go hear it or in this case read to know that everyday there is a message meant just for you..

 

[kpiotrowski]

It has been truly mind blowing all the different stuff there is to learn.. and how on most day I log in here and find something new to learn. Some times this place is alot like church you just have to go hear it or in this case read to know that everyday there is a message meant just for you..

Amen! ( don't go to church anymore but it seemed appropriate)

 

[N1Husker]

to accureatly use a hydrometer u need to have the temp altitude conversion charts. mojo told me this once.

Man, that's getting too technical, now I have a headache. I just want to look like a scientist, I don't want to be one.

 

[wes]

Actually, it is hard to beat the accuracy of a quality hydrometer unless you are spending around 10 times the hydrometer cost on a refractometer.
However, cheap hydrometers are a total waste.

That's true, I don't think she was taking the less expensive ones into consideration. She has one of the expensive ones.