Lubricate Your Refractometer

[lapin]

apéritif = Before dinner to kill any weird bacteria growing in that 2 week old chinese food as it hits the stomach.
digestif = After dinner to be sure said bacteria is really dead. Poire Williams or any other home made fire water type eau-de-vie. Extra doses are usually taken out in the barn with a cigar.

 

[jimbob928]

The pin in the hinge on my refractometer is loose enough to push out easily. Then you could dip the cover in vinegar and use a pipe cleaner to clean the holes out before lubrication. I also use these really small brushes I bought off Amazon " Viamed 100 disposable cytology endocervical sampling brush".
They are great for cleaning out small spaces in powerheads, hoses and such.

 

[jimbob928]

The pin in the hinge on my refractometer is loose enough to push out easily. Then you could dip the cover in vinegar and use a pipe cleaner to clean the holes out before lubrication. I also use these really small brushes I bought off Amazon " Viamed 100 disposable cytology endocervical sampling brush".
They are great for cleaning out small spaces in powerheads, hoses and such.

 

[siggy]

Not sure if is the brand or type, I cannot use my tank lights to get a reading, I have to turn to another light source, not because of accuracy but because I simply cannot see the reading.

 

[jsker]

Thank you @redfishbluefish for the write up.

 

[cracker]

Siggy mentioned this already about a corroded adjust screw . This happened to my old refractometer & replaced it. So I took food grade silicone & packed around the whole adjust assembly replaced the cap & scotch taped this around the housing . this hopefully will keep out any salt corrosion .

 

[Dennis McGrath]

Where are these refractometers being stored where they rust so much? It this happening from being dropped in the tank? Are you dipping it in the tank? (hint: if you answered yes, you're doing it wrong).
Maybe it would be best to store them in a large ziploc bag to prevent exposure to the salt water?

 

[cracker]

I like to leave mine in the box with the lid open so it can dry out .

 

[lapin]

Siggy mentioned this already about a corroded adjust screw . This happened to my old refractometer & replaced it.

Where did you get the screw and knurled lock ?

I kept mine in the tank room just laying around. I used to be careful and keep both in the boxes. I looked at the price of new ones and now I am keeping them back in their boxes. I always rinse it with tap water and wipe dry after use.

 

[lapin]

Not sure if is the brand or type, I cannot use my tank lights to get a reading, I have to turn to another light source, not because of accuracy but because I simply cannot see the reading.

I have the same issue with my Kessils. I have 2 ATC refractometers.

 

[cracker]

@lapin If you were asking me? I didn't even try to find replacement screw/lock ring . I just bought a new one . ATC

 

[tigé21v]

Thank you @redfishbluefish for the write up.

+1
Mine has been really tight for a while now. From time to time I've messed with it, trying to loosen it up, with no luck. I figured I just had to live with it.
I had to work on it for quite a while, but since I knew it was possible to fix it, I stuck with it. Now it's as good as new!!

 

[redfishbluefish]

For those who have entered my eleven plus year old refractometer into a beauty contest, it's even worse than you think. The rubberized sleeve is also torn.

After each use it is whipped down with a soft rag and placed back into it's container with the lid open. Even with this, after 11 years, it's not looking pretty, but because of continued lubrication, still working like a champ. That was the point of this article, keep the old equipment up and running smoothly.


I have surgical stainless steel instruments that I use in and about my tank that get rinsed with tap water after each use that have rusted up and look terrible. Now if you wish to see down right ugly, I have a couple regular steel tools that get used on the tank that are an absolute mess.

Again, lubricate your refractometers regardless if they are ugly or pretty.

 

[Brew12]

Even with this, after 11 years, it's not looking pretty

People were keeping reef tanks that long ago?

 

[aquadog]

Did you know an unlubricated refractometer will produce funny numbers?


Your refractometer has a hinged cover that goes over the angled plate of the refractometer. What happens over time is the hinges stiffen up from salt deposits, causing this cover to not sit all the way down on the angled plate. You can not see this by your own eye, but believe me, it's not fully resting on the angled plate. When this occurs, the numbers you see are no longer true. Actually this typically occurs slowly over time, and you most likely don't even realize it.

That little hinged door needs to easily and readily flop down onto the plate. If it is stiff, and doesn't fall freely, you aren't getting an accurate reading of your salinity. You can potentially offset this error by frequently calibrating your refractometer with 1.026 calibration fluid (not RO/DI water). Note that this calibration solution could also be termed 35ppt or 53 mS/cm.

However, the best thing to do is to keep your refractometer hinges well lubricated.


Now I know some of you are thinking I'm a nut case. Well, I am, but your refractometer still needs lubrication....and I'll prove it, especially if you have a stiff-hinged refractometer. What I want you to do is to measure the salinity of your tank. Now follow my lubrication instructions below and re-measure your tank (before re-calibrating). Do you see a difference? Please post your results here so others can see the truth.

So how do I lubricate my refractometer without getting lube all over the place?

Let's first see if you have stiff hinges. Take your refractometer and open the "door" so that it is sticking straigh up:

The door should readily and easily fall back down into position, and not stay in this stiffened position. If the door just stays there, you have really stiff hinges, resulting in funny salinity numbers.

A second test is to hold your refractometer upside down and move it back and forth. The door should readily and easily swing back and forth at all hinge points, with extreme ease with each back and forth motion you make. Again, if not, you've got stiff hinges.

So let's lube your refractometer!

I use WD40, but I would imagine other lubs would work just at well. Now I don't simply squirt WD40 on my refractometer....that would be a mess, and who knows what this lube would do to accurate readings? What I do is very carefully dab small amounts of WD40 directly on the hinge pins only.

So what I do is to first squirt a small amount of WD40 into a very small glass. My wife was insistent on purchasing Waterford Crystal Aperitif glasses....don't ask the price. I'm coming up on 40 years of marriage and we've never used these glasses. They sit in our china cabinet, never used......until now. Don't know what an Aperitif glass is? It's a disgustingly small glass that holds a thimble's worth of liquid that is used to serve an Aperitif or Cordial.....pinkies out.

So I'm figuring I've got to get some use out of these overpriced, never used, small glasses, so I squirt a small amount of WD40 into one of the glasses. Please don't tell my wife.

Now using a toothpick or finishing nail, I dab a small amount of the WD40 on the hinge points and then move the door back and forth to work the lube in. You'll actually feel the door free up and move easily as you are doing this.

Continue to do all hinge points with this lubrication, moving the door back and forth as you work that lub in.

Now when you attempt to put that door straight up in the air, it should immediately fall down into position.

Now for those of you doing my little test above, re-test you tank water and let me know what number you're getting....before and after lubing. Otherwise, once you've lubricated your hinges, you need to re-calibrate your refractometer. Now you are all set to get accurate numbers from your refractometer.

Finishing up, how frequently do I lubricate? I would guess it's about once a year, whenever I notice the door isn't swinging down very freely. This timing could vary widely dependently on frequency of use. I'm only doing water changes twice a month, so lube as needed to keep you refractometer humming perfectly.

Loved the story! Appreciate the info.

 

[madweazl]

Thanks - its an interesting article - Just doesn't make any difference with my refractometer (I have no clue why it doesn't) - maybe the technology is improved in 4 years. Try it with your own refractometer and report back... Mine does not change 'at all'. Now - perhaps the issue is calibrating with a different light than the light you are using - but even still - it should change if you use different light (or what am I missing)

I've never observed a difference but it would be easy enough to test; you could calibrate under sunlight and then reapply calibration solution and check it under different source.

 

[MnFish1]

I've never observed a difference but it would be easy enough to test; you could calibrate under sunlight and then reapply calibration solution and check it under different source.

Yes - Or just take a sample of your tank - look at it under one light and then look at it under a different light immediately. I did this with incandescent, daylight and my tank lights - the 'line' doesn't move at all. Like I said Im not sure why...

 

[madweazl]

Yes - Or just take a sample of your tank - look at it under one light and then look at it under a different light immediately. I did this with incandescent, daylight and my tank lights - the 'line' doesn't move at all. Like I said Im not sure why...

That doesn't get to the crux of the article though; looking at the same sample shouldn't change (according to the link) but calibrating under one and observing a sample under another would. I just didn't word it properly in the first post.

 

[Brew12]

That doesn't get to the crux of the article though; looking at the same sample shouldn't change (according to the link) but calibrating under one and observing a sample under another would. I just didn't word it properly in the first post.

I think the confusion is in the light source. It shouldn't matter if you calibrate and/or view it under lights of similar wavelength. If you calibrate it under a strong blue light and try reading it under a strong red light it will cause problems. LED/Sunlight/Incandescent doesn't matter much if they are of similar color.

 

[madweazl]

Calibration fluid under tank lights (T5/Kessil around 14k)

Tank water sample under natural light

Calibration under natural light

Tank water sample under tank lights (T5/Kessil around 14k)

Doesnt appear to be a measurable difference between my lighting and the sun.

 

[MnFish1]

That doesn't get to the crux of the article though; looking at the same sample shouldn't change (according to the link) but calibrating under one and observing a sample under another would. I just didn't word it properly in the first post.

Well so we’re on the same page. I know what the article says. But for it to be ‘true’ ie significant in real life it would suggest that looking at any sample under different lights would make a difference. Ie let’s say I calibrate my refractometer with an incandescent bulb. And measure my sg at 1.025. I then take the refractometer and look at the sample under daylight and it remains 1.025. I have now just used a different light source than the one I calibrated my refractometer and the results are the same. If I use my led lights on my tank and the result is 1.025 what does that tell you? It tells me that with the different light sources available to at least me, there is no difference. Even though in theory
There could be.