I don’t know who to trust anymore! SERIOUS PROBLEM!
- Thread starter Layne.Wilson
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MTBake
2500 Club Member
I eneded up ordering 3 brands of calibration fluid and found that the brs brand was consistently lower than Aqua Craft and Pinpoint brands. Brs sent me a new bottle and had the same issue. Gave up on their brand for calibration fluid after that.
I never did try the Hanna, fwiw. Just my experience with calibration fluids.
I never did try the Hanna, fwiw. Just my experience with calibration fluids.
Thaxxx
Valuable Member
LOL
Looks like there is no answer.
It sad as it is we have to question the accuracy of different kinds of units. Now we have to question whether the calibration fluid is accurate.
Looks like there is no answer.
It sad as it is we have to question the accuracy of different kinds of units. Now we have to question whether the calibration fluid is accurate.
Arthacker87
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Let's drive to the ocean and check all our instruments lol
Seaspirit
Community Member
My Hanna reads 1.023 when my refractometer reads 1.025, after both are calibrated. I decide on the salinity I want based on how happy the tank looks. At a Hanna of 1.025 the corals just don't look happy, they're better at Hanna 1.023 so whatever that actually is, it works for me. Also, my Tropic Marin Pro mixes up to an alkalinity of 6.7 so I have to add Part B before I use it for water changes or I'd get big swings, am trying to maintain alk around 8.5 to 9. You're not alone in trying to figure out this stuff!
Hermie
Valuable Member
Would it be helpful to make a DIY 35 ppt calibration solution using NaCl and distilled water as Randy has previously recommended? I did that a week ago to check my hydrometer and turns out that I've had a consistently high salinity for over a year...
You mix up 6.20 grams NaCl (table salt) with 161 grams of RODI water. Then use that, it's just about 35ppt "exactly."
You mix up 6.20 grams NaCl (table salt) with 161 grams of RODI water. Then use that, it's just about 35ppt "exactly."
I have been using my Hanna and never a issue.
Calibration fluid for refractometers is garbage. I have tons of bottles and most read different even the same brands. One thing when using them make sure you shake bottle.
Calibration fluid for refractometers is garbage. I have tons of bottles and most read different even the same brands. One thing when using them make sure you shake bottle.
I'll just say it again.
Calibrated both the refractometer and Hanna with their respective calibration fluids.
Then used the refracto juice to test both and got the exact same reading of 35. This meant to me, that for a room temp known salinity they both agreed.
For the tanks, the Hanna read 1.024 while the refractometer read 1.028. They use different technologies to measure salinity. We know temp impacts reading. My refractometer is ATC, so it should compensate.
I think the problem lies in the refractometer calibration. See article:
joejaworski.wordpress.com
Basically, the refractometer itself needs to be calibrated at the right temp for it to be accurate and temp adjust correctly.
I trust the Hanna.
Calibrated both the refractometer and Hanna with their respective calibration fluids.
Then used the refracto juice to test both and got the exact same reading of 35. This meant to me, that for a room temp known salinity they both agreed.
For the tanks, the Hanna read 1.024 while the refractometer read 1.028. They use different technologies to measure salinity. We know temp impacts reading. My refractometer is ATC, so it should compensate.
I think the problem lies in the refractometer calibration. See article:
Refractometers are Never Accurate- Unless you do these Fixes
Over the 40 years that I’ve been in this hobby, I acquired lots of salinity measuring devices. In the 1970’s, everyone was using stem/bulb hydrometers. These were fragile glass instruments about 12…
joejaworski.wordpress.com
Basically, the refractometer itself needs to be calibrated at the right temp for it to be accurate and temp adjust correctly.
I trust the Hanna.
Skynyrd Fish
Valuable Member
So your main issue is your corals are not looking great. Time for an ATI water test. Also your refracto meter may be off. Mix some tropic marin pro up using the Hanna. Then test alk. If your alk is where you think it should be then there’s your answer.
I too had no luck finding trustable / repeatable results with the analog refractometers.
It costs an arm and a leg, but I am very happy with my misco palm abbe.
It calibrates with RODI / distilled water, reads 0.000X digits (one more than others available in the hobby) and has a +-0.0005 accuracy. I’ve validated with various standards and it’s consistent with my older Milwaukee digital refractometer which is a much more reasonable price. However with the palm abbe I can shoot for 1.0265 on the nose, and am less worried about scratching the measuring surface over time.
It costs an arm and a leg, but I am very happy with my misco palm abbe.
It calibrates with RODI / distilled water, reads 0.000X digits (one more than others available in the hobby) and has a +-0.0005 accuracy. I’ve validated with various standards and it’s consistent with my older Milwaukee digital refractometer which is a much more reasonable price. However with the palm abbe I can shoot for 1.0265 on the nose, and am less worried about scratching the measuring surface over time.
I’ve also been going nuts lately trying to figure out what is correct. I now have 2-bottles of BRS, 2-bottles Brightwell and 1-bottle AquaCraft.
My BRS bottles are about 5ppt lower than the Brightwell bottles and the AquaCraft is in between the two at about 2.5ppt higher than BRS and 2.5 lower than Brightwell.
I’m tired of thinking about it, so I’m going with the middle, AquaCraft.
Seems like getting salinity right is a difficult problem in this hobby. I was going to ask a similar question but it seems like there is no solution other than a 100+ dollar lab grade probe. Bad refractometers and bad calibration solutions leaves us all guessing.
MTBake
2500 Club Member
I have been using Pinpoint since 2007 or so and have no reason to doubt the quality of that brand. AquaCraft is good for verification purposes as it seems to match what I get with Pinpoint. I'll order a bottle of Brightwell and report back. Fwiw, I haven't tried the brs stuff in about 18 months.
SliceGolfer
Well-Known Member
Another simple test to confirm is to test Alk and Ca on newly mixed saltwater. Mix a sample for each the refractometer and the conductivity tester, mix each to 35ppt based on the reading of each device. See which one is closest to the TM Pro Reef salt, or whichever salt brand used. If the values are way under, then that device may have calibration issues.
Is calibrating a Refract with rodi set to 0.00 not a thing? Asking for a friend lol
Unfortunately it’s not accurate with our refractometers.
If you have a decent balance, a reasonably calibrated thermometer, and something like a 100 mL volumetric flask, you can readily determine the density of your water at a given temperature (hopefully 20C), and from that, determine the specific gravity with pretty good accuracy. I've written about it before.
I haven't used the Hanna, but second earlier posts that the Milwaukee has served very well. The commercial calibration solutions are junk. Used different brands, and they all yield different results. The temperature of refractometer glass, the calibration solution, and time to equalize all make calibration not as straightforward. So far, the best calibration solution I've found is a self made one.
www.reef2reef.com
It can be made by dissolving 3.65 grams of sodium chloride in 96.35 grams (mL) of purified freshwater. I use a scale with 100ths of grams to make it. With my Milwaukee, I will zero with 0 TDS RODI, and when I use this solution, I get exactly 35ppt.
DIY Salinity calibration solutions
Randy, In light of another post on calibrating a conductivity meter, I decided to give it all a shot on my own system. I read through your article on DIY salinity calibration (http://www.reefkeeping.com/issues/2004-06/rhf/) and have a few questions for my simple brain. 1. Is the Brand MORTON...
www.reef2reef.com
It can be made by dissolving 3.65 grams of sodium chloride in 96.35 grams (mL) of purified freshwater. I use a scale with 100ths of grams to make it. With my Milwaukee, I will zero with 0 TDS RODI, and when I use this solution, I get exactly 35ppt.
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