Refractometer help

[Ding2daDong]

Well I finally chucked my stupid swing arm salinity tester. Just wondering if anyone has any recommendations for refractometers. I don't know the difference between one or the other. They all seem the same.

Some say 0-10% while others say 0-32%?

I was looking at this one

http://cgi.ebay.com/Salinity-Refrac...ryZ20755QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Any help would be appreciated.

Matthew

 

[loyalrogue]

It looks just like the one I bought off of ebay.
Here is the guy I bought mine from: http://rover.ebay.com/rover/1/711-1...=2055638&mpre=http://stores.ebay.com/Greatdel

It was also made in Hong Kong, probably by the same exact manufacturer as the one you posted.
The only difference is your guy gives a "buy it now" price and gives you extra disposable pipettes, and my guy only does auction style bidding and gives a hard storage case.
Personally I would much rather have the hard storage case instead of those disposable pipettes.

Let me just say that I love my refractometer!!!
I used those swing-arm pieces of garbage for waaaay too long.
It was always a crapshoot, and everytime I thought I knew what my SG was I'd take a sample to the LFS and find out I was so wrong.
Now my SG is EXACT and accurate every time.
Those things are a Godsend.
Even if some people are brand snobs and turn their nose up at a cheap foreign refractometer, I can say with 100% certainty that this one has been nothing but a reliable and quality tool every bit as good as the $100 model at my LFS. (which I still compare readings to every few months without any difference)

I say go for it.
It will be one of the cheapest and best investments you could make.

 

[Ding2daDong]

Thanks for the reply. I guess I will try them out.

Next mission is to by a 6stage RO/DI unit w/ TDS meter on ebay...
Word on the street is there are some nice ones for under $130, or that is what Ive been hearing.

Thanks again

-Matthew

 

[loyalrogue]

That's my next purchase too.

I'm just waiting until I get my 5000 points at Big Al's to get my free $200 gift card before I stop buying my water there.
(only another 435 points to go)

 

[db_triggerfish]

loyalrogue, thanks i we watch one and buy it at $ 9.99 he has a lot of them so i am sure some will not get any bids.
i have two different type of swing arm both have different readings.

Thanks,

 

[instrance]

Greadel is a good seller I bough his ph meter and refractometer. The both work great!

 

[ninjamini]

What do you all think about this one?

http://www.drsfostersmith.com/produ...&Ntx=mode+matchallpartial&Np=1&pc=1&N=0&Nty=1

 

[REDDAWG43]

ok everyone has or is getting arefractometer...
My question is: What is everyone using to calibrate them?
I heard something about calibration fluid. Has anyine used it and is it sold locally at LFS?

 

[loyalrogue]

I use distilled water to calibrate it to 1.000... simple.

 

[jeffbrig]

<a href=showthread.php?s=&postid=9390218#post9390218 target=_blank>Originally posted</a> by loyalrogue
I use distilled water to calibrate it to 1.000... simple.

Careful with that John. My refractometer was calibrated to 1.000 with RO/DI water, and read .004 low at natural saltwater levels. Randy Holmes Farley had an article about this in ReefKeeping a few months ago. Much better to calibrate with a known standard at the range where you'll be measuring.

I gave up on refractometers after that happened, and bought a pinpoint salinity meter. Much easier, especially if you need to monitor multiple tanks.

 

[ninjamini]

<a href=showthread.php?s=&postid=9393092#post9393092 target=_blank>Originally posted</a> by jeffbrig
... and bought a pinpoint salinity meter. Much easier, especially if you need to monitor multiple tanks.

Is there a good (cheap) place to get one?

 

[loyalrogue]

<a href=showthread.php?s=&postid=9393092#post9393092 target=_blank>Originally posted</a> by jeffbrig
Careful with that John. My refractometer was calibrated to 1.000 with RO/DI water, and read .004 low at natural saltwater levels. Randy Holmes Farley had an article about this in ReefKeeping a few months ago. Much better to calibrate with a known standard at the range where you'll be measuring.

I gave up on refractometers after that happened, and bought a pinpoint salinity meter. Much easier, especially if you need to monitor multiple tanks.

Thanks for the heads-up, Jeff.
I just read the article here if anyone is interested: http://reefkeeping.com/issues/2006-12/rhf/index.php#11

So because of possible slope miscalibration it's safer to guard against a faulty refractometer by calibrating with a solution at 35 ppt (1.0264 sg) instead of calibrating at 1.000 with pure water.

For anyone too lazy to read the article, you can make a 35 ppt solution by disolving 1/4 cup (73.1 g) of Morton's Iodized Salt into two liters (2000 g) of pure water.

Looks like pinpoint salinity monitors are going for around $120 on Ebay. http://rover.ebay.com/rover/1/711-1...ftrt=1&ftrv=1&saprclo=&saprchi=&fsop=1&fsoo=1

 

[bckane]

I gave up my Refractometer...donated it to the frag swap raffle, went with Jeff pinpoint salinity meter.

 

[jeffbrig]

<a href=showthread.php?s=&postid=9393578#post9393578 target=_blank>Originally posted</a> by loyalrogue
Thanks for the heads-up, Jeff.
I just read the article here if anyone is interested: http://reefkeeping.com/issues/2006-12/rhf/index.php#11

So because of possible slope miscalibration it's safer to guard against a faulty refractometer by calibrating with a solution at 35 ppt (1.0264 sg) instead of calibrating at 1.000 with pure water.

For anyone too lazy to read the article, you can make a 35 ppt solution by disolving 1/4 cup (73.1 g) of Morton's Iodized Salt into two liters (2000 g) of pure water.
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No problem...

Bottom line - if you calibrate at 35ppt, your refractometer is guaranteed accurate to measure 35ppt saltwater.

As far as the DIY calibration solution, Randy later came back and said that it isn't terribly accurate because there's too much variation between 2L bottles. Pinpoint sells a 53mS calibration fluid that can be used to calibrate a refractometer, but make sure its Pinpoint, since not all calibration fluids have the same refractive properties as saltwater.

 

[jeffbrig]

<a href=showthread.php?s=&postid=9393292#post9393292 target=_blank>Originally posted</a> by ninjamini
Is there a good (cheap) place to get one?

I got mine from aquatic ecosystems for about $115, if I recall. I think they give you a price break if you place an order for 3, in case a few want to get together on an order.