Lawnman Posted June 13, 2009 Share Posted June 13, 2009 Ok this has got me puzzled. I got a new refractometer the other day from my LFA the said they are usually calibrated from the factory. Ah ok so I cam home checked my salinty and it was 1.025 not bad I thought.My hydrometer said about the same thing.Well I was at premium aquatics today and decided to get some pinpoint calibratiom fluid to check it out.WOW it was way off by the calibration fluid. So I adjusted it to 35 or 1.026 like it said and tested my water it said it was 1.010 I believe I have these numbers right. It said my salinty was super low. So I decided to check the fresh saltwater I had in a 5 gallon jug from my LFS that usually runs 1.025 and it said it was super low like 1.010 so I was puzzled so I got some snails from premium aquatics today so I decided to test there water which is usually around 1.022-1.025 and it read super low. So three things that usually read correctly now are reading SUPER low since I calibrated my meter with this fluid.WTF what should I do? Brad Link to comment
Littlegreeny Posted June 13, 2009 Share Posted June 13, 2009 I am also wondering about the accuracy of their calibration fluid. I think my bottle might be off by at least 0.003 points. Very interesting... Ok this has got me puzzled. I got a new refractometer the other day from my LFA the said they are usually calibrated from the factory. Ah ok so I cam home checked my salinty and it was 1.025 not bad I thought.My hydrometer said about the same thing.Well I was at premium aquatics today and decided to get some pinpoint calibratiom fluid to check it out.WOW it was way off by the calibration fluid. So I adjusted it to 35 or 1.026 like it said and tested my water it said it was 1.010 I believe I have these numbers right. It said my salinty was super low. So I decided to check the fresh saltwater I had in a 5 gallon jug from my LFS that usually runs 1.025 and it said it was super low like 1.010 so I was puzzled so I got some snails from premium aquatics today so I decided to test there water which is usually around 1.022-1.025 and it read super low. So three things that usually read correctly now are reading SUPER low since I calibrated my meter with this fluid.WTF what should I do? Brad Link to comment
poidog Posted June 13, 2009 Share Posted June 13, 2009 check it against distilled water which should be at 0. Link to comment
inTank Posted June 13, 2009 Share Posted June 13, 2009 Something is wrong with that. How did you apply the solution? Was it at 77°? There is no way you had a tank at 1.010 and things were living. I used the same solution and my refractor was off by just a few. I am also wondering about the accuracy of their calibration fluid. I think my bottle might be off by at least 0.003 points. Very interesting... 0.003 is so low I can't see how your eye can even see that difference Link to comment
Lawnman Posted June 13, 2009 Author Share Posted June 13, 2009 I am going to get some distilled water today. I did a search about this on this website and came up with 2 other people that had the same problem. It has me puzzled I am going to get some dist water today and check it. Then I am going to check my water to see what it says. Then I am going to take some of my water and put it in a sealed container and take it to the LFS and see what they meter says. If my meter and there meter match after I calibrate it with distilled water I am going to pitch this calibration fluid. My meter says calibrate with dist water but everyone kept talking about how good the calibration fluid was so I got some. I will update later once I figure this out. Brad Something is wrong with that. How did you apply the solution? Was it at 77°? There is no way you had a tank at 1.010 and things were living. I used the same solution and my refractor was off by just a few. 0.003 is so low I can't see how your eye can even see that difference No the poster was saying it was of my .003 not that it was that. Yes it was correct temp I floated the bottle in my tank for 4 hours after I got the false reading and still got the same reading. 1.010 is what I was thinking that is what puzzled me.I first started to slowly bring up the salinity then I said wait a minute this can't be right.A hydrometer is junk but it can't be off that bad. Brad check it against distilled water which should be at 0. I am going to do that as soon as work is done today. Brad Link to comment
masterbuilder Posted June 13, 2009 Share Posted June 13, 2009 I bought some too....dont trust it for similar reasons. Link to comment
masterbuilder Posted June 13, 2009 Share Posted June 13, 2009 Fosi is right. But the Pinpoint solution I received is obviously faulty. In my case, I had been using only distilled to check my refractometer and mixing saltwater with this refractometer for over 3 years. Corals and livestock have always done well. Salt mixes very close at about 1/2 cup per gallon and then adjusted up/down as needed. When I checked my refractometer using the Pinpoint Solution it showed 1.014 ..... I don’t think so! I doubt that my corals would be very happy at all at the level. Again, I agree that a 2 point calibration is best...just not with the Pinpoint brand. It seems that their QC is lacking IMO. Mark p.s. Bought mine from Marine Depot, so the likely hood that it had been sitting on the shelf forever is low. Link to comment
121a Posted June 13, 2009 Share Posted June 13, 2009 i bought some a while ago, over a year and it is fine. did anyone contact them and tell them, so more people don't find they have "lower salinity" and quickly mix buckets of higher SG water to raise their salinity... Link to comment
Littlegreeny Posted June 13, 2009 Share Posted June 13, 2009 0.003 is so low I can't see how your eye can even see that difference It's very easy to see a difference of 0.001 units on my refractometer, and I have the blue "made in china" one most people have...Just make sure you view it using a strong light source. Link to comment
Lawnman Posted June 13, 2009 Author Share Posted June 13, 2009 Fosi is right. But the Pinpoint solution I received is obviously faulty. In my case, I had been using only distilled to check my refractometer and mixing saltwater with this refractometer for over 3 years. Corals and livestock have always done well. Salt mixes very close at about 1/2 cup per gallon and then adjusted up/down as needed. When I checked my refractometer using the Pinpoint Solution it showed 1.014 ..... I don’t think so! I doubt that my corals would be very happy at all at the level. Again, I agree that a 2 point calibration is best...just not with the Pinpoint brand. It seems that their QC is lacking IMO. Mark p.s. Bought mine from Marine Depot, so the likely hood that it had been sitting on the shelf forever is low. Ok I agree 1000 percent. There crap calibration fluid is off by .015 When I calibrated it with there snake oil it said my water was 1.010 I about crapped my self so I started to raise my salinity. I mean it is calibration fluid how could it be wrong. So I got some distelled water and calibrated it to zero. Checked my water and it was 1.027 so I took some of my water went to the LFS and they checked my water and they said it is 1.027 then they checked it with another refratometer and it was again 1.027 so then they used my calibration fluid and the owner of the LFS was ticked off because they sell the same solution. He pulled all three bottle of his calibration fluid and checked all 3 all 3 gave him different readings in range from .005-.016 He said he was contacting them on Monday. Link to comment
Littlegreeny Posted June 13, 2009 Share Posted June 13, 2009 Ok I agree 1000 percent. There crap calibration fluid is off by .015 When I calibrated it with there snake oil it said my water was 1.010 I about crapped my self so I started to raise my salinity. I mean it is calibration fluid how could it be wrong. So I got some distelled water and calibrated it to zero. Checked my water and it was 1.027 so I took some of my water went to the LFS and they checked my water and they said it is 1.027 then they checked it with another refratometer and it was again 1.027 so then they used my calibration fluid and the owner of the LFS was ticked off because they sell the same solution. He pulled all three bottle of his calibration fluid and checked all 3 all 3 gave him different readings in range from .005-.016 He said he was contacting them on Monday. Thanks for doing this Lawnman. I plan on doing the same thing as you. I recently purchased the pinpoint calibration fluid at Dr's F&S. I previously always calibrated my refractometer using only distilled water, but read about others on here having problems calibrating with just distilled water. I've never had problems with my tank and am not going to chance the hundreds of dollars worth of livestock I have in my BC8 to some crappy, so-called "calibration" fluid. Link to comment
dflash Posted June 17, 2009 Share Posted June 17, 2009 OK.. very good info here, but who can tell me what the refractometer should read when using the Pinpoint Calibration Fluid? Link to comment
Jacobnano Posted June 17, 2009 Share Posted June 17, 2009 Why buy that stuff when RO water will give you the same result (seems like a better result in this thread)? I don't get it... Link to comment
StevieT Posted June 17, 2009 Share Posted June 17, 2009 Why buy that stuff when RO water will give you the same result (seems like a better result in this thread)? I don't get it... you don't test salt at 0. You test it at a level. Same as a scale with weight. You don't calibrate it to zero. You calibrate it to known weights. It's very easy to see a difference of 0.001 units on my refractometer, and I have the blue "made in china" one most people have...Just make sure you view it using a strong light source. you are correct. I wasn't thinking in the correct 0.00x sense Link to comment
Jacobnano Posted June 17, 2009 Share Posted June 17, 2009 Why you always hatin dawg? Wouldn't RO water contain 0 traces of salt so you calibrate the refractometer to that zero? Then compare that to the tank? Link to comment
StevieT Posted June 17, 2009 Share Posted June 17, 2009 umm. your tank has salt in it, not fresh water. your scale has weight on it, not air Link to comment
filefish949 Posted June 17, 2009 Share Posted June 17, 2009 Two-point calibrations FTW. Fosi is right. But the Pinpoint solution I received is obviously faulty. yep, however you can't very well adjust the slope on a refractometer.... it is "cast in stone" at the factory do not calibrate with RO/DI to zero, use 35ppt solution. it is not uncommon for refractometers to be off by several points out of the box, and it is rather common for the slope to be wildly skewed. while testing with 35ppt solution is no assurance that your instrument is not inaccurate for most of it's scale, at least it will be accurate for the value you are testing for. RO/DI "zeroing" gives no such assurance. i just use one of these, much more accurate, however not as precise Link to comment
Jacobnano Posted June 17, 2009 Share Posted June 17, 2009 O ok. Still kinda confused but whatevah Link to comment
filefish949 Posted June 17, 2009 Share Posted June 17, 2009 for clarification, the only adjustment you can make with a refractometer is to move the red line left and right, there is no adjustment for the angle of the red line (slope) if you were to align the red and green lines at 0(with RO/DI), then they would be off at 35ppt, in this illustration, while the refractometer is inaccurate everywhere else, at least it is accurate at the value we are targeting HTH Link to comment
dflash Posted June 17, 2009 Share Posted June 17, 2009 Ok .. so no one has answered the question above.. The fluid I have reads PINPOINT Salinity Monitor 53.0mS Calibration Fluid +/- 1% @77 F/25 C..... what does that mean?? Does that mean that I should calibrate my refractometer to 53? Link to comment
StevieT Posted June 17, 2009 Share Posted June 17, 2009 no should calibrate my refractometer to 53? 35 Link to comment
filefish949 Posted June 17, 2009 Share Posted June 17, 2009 Ok .. so no one has answered the question above.. The fluid I have reads PINPOINT Salinity Monitor 53.0mS Calibration Fluid +/- 1% @77 F/25 C..... what does that mean?? Does that mean that I should calibrate my refractometer to 53? sorry, don't use that. it is the wrong stuff, it is for calibrating a conductivity monitor.. bling bling super accurate comes in a gold packet with a paper white sticker?? yep, don't use that for a refractometer Link to comment
StevieT Posted June 17, 2009 Share Posted June 17, 2009 sorry, don't use that. it is the wrong stuff, it is for calibrating a conductivity monitor.. bling bling super accurate comes in a gold packet with a paper white sticker?? yep, don't use that for a refractometer no. the pinpoint calibration solution comes with with the sticker listed by dflash. I have the same bottle. Confused me when it came in. Thank you Stevie the sticker is stupid. But try and get he solution to 77°. I warmed mine in the microwave Link to comment
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