If you own a refractometer, read this

[pk1]

I've been testing my SW for 5 years with a piece of garbage. A Milwaukee SMS100ATC, calibrated with RO/DI just like the directions say. 1.025 for 5 years now. This may be old news to some of you, but the only info I had read about these POS's was about the crappy blue ones. Looks like they are all crap. Browsing the chemistry forum I came across this thread:

http://www.reefcentral.com/forums/showthread.php?threadid=953605&perpage=25&pagenumber=1

Here is my thread confirming this:
http://www.reefcentral.com/forums/showthread.php?threadid=962460

I ordered 2 bottles of this stuff, and sure enough I tested my water after calibrating with the pinpoint fluid and my tank had a SG of 1.020. What a joke. Another reef keeping falsehood uncovered.

Patrick

 

[jcm1229]

Thanks for bring that up. I have used a refractometer (mine was a bit more expensive - not that it makes it any better!). I think I have soem of the pinpoint solution laying around. I'll check mine and post what I find.

 

[nmprisons]

now you have me all worried. would it be safe to assume that if another devise (maybe a LFS refractometer) tested my water at the same salinity then my refractometer was fine?

 

[Pufferpunk]

We had the head chemist from the Shedd Aquarium speak at our last CMAS meeting. He swears by the simple swing-arm hydrometers. Said they were actually better than refractometers, but I don't remember why. Anyone here remember?

 

[pk1]

I would not feel confident with ANY refractometer now-the solution is only a few bucks at premium aquatics, well worth it IMO.

 

[pk1]

Puffer-he didn't really give a reason, just said they where crap.

 

[karenL]

I feel as though my very existance has been a lie
what can one believe in
what can one trust
the lies, all in the name of making money off the marine aquarist community
1st IO, now refractometers
when will it stop!

 

[NewSchool04]

how do you use the solution?

 

[mbunaman]

At least I dont feel bad about dropping and breaking mine a few days ago. What would you recommend for accurate results. I have the swing arm one on backup but I know with those the temperature has to be at a certain degree to work properly.

 

[pk1]

Pat-you use the soultion the same way you test your water, add a few drops and adjust until it reads 1.026. For accurate results I would use a Pinpoint Salinity Monitor, or a refractometer that has been calibrated with the pinpoint solution, personaly I don't like the swing arm types-that's just me though-

 

[Pufferpunk]

Ya know, everyone's panicking here. Your tank looks great at what ever steady SG you're keeping it at now right?

Here's a discussion going on at my forum now:
http://www.thepufferforum.com/forum/viewtopic.php?t=1886

BTW, the fellow posting as nmonks is a scientist in England.

 

[pk1]

Puffer, I have disagree. I don't think there is any reason to keep these delicate animals in anything less than the closest possible replication of the environment they live in. BTW, Randy Holmes-Farley is a scientist too . And I don't trust the English!! j/k

 

[Racenrich]

its like all things....you get what you pay for...i have a NIST certified Refract from VWR, a very respectiable laboratory supplier.
Ran close to $90...worth every penny.

BTW....if you used the same refrac for 5yrs and it gave you the same results all the time, then you can say that you were consistatly low all this time....to me that isnt that bad. now if it gave you results all over the place....well then.....time for a new one.

HTH

 

[ostrow]

Pat, you never posted after RHF-s comment that he would trust the ATC and suspect the fluid. Did you test against his DIY calibration?

 

[NewSchool04]

I'm affraid to even see what mine would turn out to be. I use the blue refractometer everyone is dumping on.

 

[whiirly]

karenL
Sorry to get off topic but I love the avatar

BTW any one local carry this solution I really dont want to spend the time to try to make my own

 

[Pufferpunk]

Mine is a black ATC. Is that one any better?

 

[DragonFish]

Hang on... whats wrong with IO???

 

[ostrow]

I'd say given what is in those threads, that any cheap refractometer, and that pretty much includes every refractometer any of us has (unless you paid over $100 from a science lab supplier) needs calibration. As I am lazy (on this) and don't want to make RHFs salt solution, plus there seems confusion on the real size of the 2L bottles, I'll just buy the $3 fluid and calibrate to that.

 

[pk1]

Joel, not sure but I think he meant that the auto temp compensation part of the refractometer he would trust but not the factory reading with RO/DI part-but I can see how his reply can be taken either way so I asked him to clarify-we'll see. I would make his DIY but I don't have a scale. Puffer-that's the same one I have.