4 diff refractometer and 4 diff reading!???

[Ahbaloch]

What to do!??

Tank is a week into cycle, i have added couple bacteri booster,

Added 5 gallong salt water from petco,

And made the rest 50 gallon w my rodi system and reef crystals.

But i got 4 diff rafrac meters and i got 4 different readings!?

 

[Dan I]

The last picture is a refractometer, the rest aren't. I had to re-calibrate my refractometer due to it giving me false readings. Look up calibration fluid for refractometers on amazon.

 

[ncaldwell]

If the last one is calibrated I'd go with it. The plastic floating arrow ones are usually off by a little, with air bubbles and other random stuff messing with the plastics buoyancy.

 

[Ahbaloch]

I have ordered some calibration fluid already

 

[TaylorPilot]

I agree that I'd go with the last one. I typically get two different bottles of calibration fluid. I double check them against each other, it's cheap insurance.

 

[ronl]

Looks like the ones in the first and third pics are showing the same reading. Let us know what the refractometer shows after you get the calibration fluid.

 

[Flippers4pups]

Your first three pictures are hydrometers and yes they are inaccurate. As stated, the Refractometer is best calibrated with calibration fluid.

 

[mkj]

take your refractor to fav LFS. Ask them what they keep their water at. Test your refractor in their tanks. Now you know what your refractor is off by. Make a mark on your refractor of LFS salinity.

I keep my salinity same as my LFS but anyone can now adjust up and down to their liking once they know where accurate mark is..

 

[mkj]

double post

 

[Ahbaloch]

So the calibration fluid came in the mail today, i will calibrate it tomorrow and see whatsup with the plastic ones and how off they are

 

[chris k.]

I agree with mkj. Just stick with one. I have a refractometer and a hydrometer. I use the hydrometer mostly because it is easier to read. But i check it with the refractometer occasionally.

 

[ronl]

I agree with mkj. Just stick with one. I have a refractometer and a hydrometer. I use the hydrometer mostly because it is easier to read. But i check it with the refractometer occasionally.

+1. I do the same thing. I know when my refractometer reads 1.026 my hydrometer reads 1.025. So I use the hydrometer more often because it is quicker and easier. But still check with the refractometer occasionally to confirm or anytime I don’t get the reading I expect on the hydrometer.

 

[reefwiser]

Throw the swing arm one's away and use the refractometer one. Hydrometers are horrible and useless but new users like them to they have things die on them because of low or high salinity.
Best is a electronic unit.

 

[Randy Holmes-Farley Verified Community Expert]

take your refractor to fav LFS. Ask them what they keep their water at. Test your refractor in their tanks. Now you know what your refractor is off by. Make a mark on your refractor of LFS salinity.

I keep my salinity same as my LFS but anyone can now adjust up and down to their liking once they know where accurate mark is..

Why would you assume the LFS knows their water salinity accurately?

Reminds me of a true story I read years ago about time keeping in the 1800's. There was a town with a jeweler who was highly respected. He had lots of high quality time pieces in his store window.

There was also an army fort nearby. Each day at "exactly" noon they would fire off their cannon.

When an unusual natural event happened (an earthquake) and scientists wanted to know the exact time, everyone in the town said it happened at 3:35 (I forget the actual time in the true story).

On further investigation, it turns out the whole town was well off of accurate time keeping.

Why?

Turns out the soldier in charge of the cannon firing got his "correct" time from the jeweler window time pieces.

But the jeweler actually got his "correct" time from the firing of the cannon.

As the days went by, the time drifted farther and farther from"real" time.

 

[reefwiser]

So the calibration fluid came in the mail today, i will calibrate it tomorrow and see whatsup with the plastic ones and how off they are

Problem is the calibration fluid is designed to be used with a refractometer. The amount of fluid used in the Hydrometer would require several bottles of refractometer calibration fluid.

 

[Erica-Renee]

I have a instant ocean Swing arm hydrometer . A Scientific instruments floating hydrometer ( most expensive ) and two refractometers (one expensive one cheap.

Both refractometers never stay accurate... The Swing arm is off by a bit .. the floating hydrometer well its chemist grade . I use the floating hydrometer to check the swing arm from time to time and have found swing arm hydrometers are usually off a bit when they are new.. If you rinse them with fresh water after each use and store them upside down they will last nearly forever.......

I Recommend taking your hydrometer and test it against properly calibrated refractometer or floating glass hydrometer... make how much its off and use it...

the key is stability.. if you are slighty off and stick with that you will be ok... but using a tool that must be calibrated over and over will not give you stable results.....

This is from how i do it not a biased opinion towards a geeky toy...... Home Aquatic refractometers are just that . a geeky toy

my opinion

 

[Kershaw]

It has been some time since I used a hydrometer. But I believe you are supposed to soak those in ro water for several hours before use. Then once salt and what not starts building up in places you can see they become more and more in accurate. Just use a refractometer and don’t for to get to check calibration. I had a cheap eBay one that held calibration perfectly. But it fell and broke the little cover. Bought a marine depot one and have to calibrate often.