I keep learning thanks Jagermeister

[roadracn]

As I continue in this hobby, I would like it to be known that I have never said that I know it all. I read a lot of threads on our Reef Club, and it always seems that I learn little tid bits here and there. Recently I read "Anyone know where to get Pinpoint refractometer calibration fluid or similar locally?" and I actually thought that I was going to be able to help someone out and just let him know that all you have to use is Ro or distilled water in order to calibrate the meter. I followed the thread with intrest after I was told that I was doing it correctly as the instructions say to do, but that it actually was not going to be accurate. I spent a couple of days reading into the topic, and getting several different ideas on how to properly calibrate the meter. I made several batches to cross check my solution and make sure that everything added up correctly, and what I found was almost unbelieveable. My refractometer that I spent 100.00 online, that I bought to replace my plastic one that I knew was off, was in fact also off. I have been fighting problems with my tank for sometime, since a crash that happened almost 18 months ago, and have asked my friends on here for advice time and time again, and you guys have thankfully helped me out time and time again. ...on now to add my .02 and let anyone on this board know what I have found out.

For starters, I am going to order another solution from someone to confirm my findings, but here is what I have found. I have chosen to keep my reef tank at 1.026 because I saw 1 time on a tank of the month that was the setting he went for. My water is well mixed and warm prior to doing water changes, and I make sure its set as close to 1.026 as I can. I checked the tank settings prior to making any adjustments, and it read a perfect 1.026. I made a saltwater solution consisting of 1tsp of table salt, and 161 ml of RO water. This, according to the chemists on the boards, will make a perfect salinity of 1.026 of which I used to calibrate the meter. I made 5 different batches, using 3 different measurement methods, and was able to get consistant readings from all 3 mothods. My meter was off by a whopping .007. I have to check it over and over just to keep my head on strait. What this means is my tank although I thought it was 1.026 is actually at a corrected 1.019, and I wonder why the corals arent colorful and the fish are stressed. I also did some more research, and called most of the LFS in Denver Metro asking for a fluid to calibrate the meter with, and I got the same response at every single store....use RO water to calibrate the meter. How is it that the so called experts in the hobby that we are in dont know that what they use and tell people is for the most part incorrect, not on something complicated NO3 management, but the easiest (or so I thought) principle Salinity.

[Zooid]

hmmmm, very interesting. I stopped reading because they were talking about grams per liter. I guess I shoulda wiped the drool from my mouth and read further. 1 teaspoon per 161ml of RO? That's easier for me to understand than grams. I'm not a drug dealer and I'm not a chemist so I don't really have a scale to measure grams hehe.

[Jagermeister]

Glad I could help!

I have also just gone through this. My refractometer was off by 0.005 so my reef was running at 1.021 rather than the 1.026 I thought it was running at.

[icantremember]

I was in the same boat. Thought I was 1.026 and really was 1.020. I have been adding 2 12oz cups of Tropin Marin a day to get the salinity up. It's coming up slowly, get about .001 per day. I am at 1.022 now.

I was at Animal Attractions this weekend and a customer brought in a couple of refractometers to be calibrated. They grabbed some RO and set them for 1.000. I think that is the norm for calibration methods.

[spstimie]

http://www.1911encyclopedia.org/Vinegar

"In preparing malt vinegar, an infusion of malt is prepared by extracting it with water at 72°, then at a higher temperature and finally at the boiling-point. After cooling the extracts are fermented with yeast, and the product kept for some months before acetification. This step can be effected by the quick process as described above, or by the slow process. In the latter the liquid at 25° is transferred to barrels lying on their sides and the fermentation allowed to proceed. When the process is complete the product is filtered through rapes in a fining tun. This is a cask fitted with a false bottom in which are placed spent tanner's wood, shavings, or, better, the pressed stalks and skins of grapes and raisins from wine manufacture. Household vinegar is made in upright casks; after twenty-four hours it is transferred to a similar cask, and the process repeated in a third and fourth cask. Malt vinegar is sold in four strengths designated 18, 20, 22, 24, the last being "proof" vinegar, containing 6% of acetic acid and having a specific gravity of 1.019. These numbers represent the grains of dry pure sodium carbonate, which are neutralized by one fluid ounce of the vinegar."

if this article and everything else i have read is correct then a 6% acetic acid malt vinegar should have a 1.019 specific gravity @ just about or a little over room temperature. i thought i would check vinegar since we use it to clean things as well. if this is true you can clean your refractometer(hydrometer in my case) and calibrate it as well.

[Ebmorri]

The reason for calibrating with a known "1.0264 sg" solution is because of the drift of the recratometer as it goes up. Meaning that when you calibrate with DI water it will always be correct with DI water how ever once you test other items the higher the SG the larger amount of error you will have.

[reefkoi]

From the title I thought it was a drunken post @ 12 a.m. LOL bummer............
C

[Zooid]

Originally posted by reefkoi
From the title I thought it was a drunken post @ 12 a.m. LOL bummer............
C

ROFL

[roadracn]

why change mediums ie, why move to vinegar when its so simple and proven to ake the known good salt solution?

[TxOilman]

Now the trick for most of us that have refractometers is to find something that accurately measures 161 ml!

[roadracn]

TX this is what I did. I took a NO3 test kit that had a 12 ml testtube and carefully filled it to 12ml and repeated 13x and then filled it to 5ml and mixed it together. I did that 2x to maintain no mistakes, For a 3rd cross refrence I also used a liquid Measuring cup that my GF had that for some reason also measured ML. I did the test there 2x to maintain no diffrences. I also did 1 test using a syrnge that came with test kits and/or joes juice. I noticed some varience between 5ml in the syrnge and 5ml on the test tube from any test kits. All other tests were conclusive and showed the same measurement +/- .0005 yes .0005 not .005 with the test tube. The syrnge was not as close. I concluded that the test kit test tube would be the way that most people would use. Its a bit time consuming, but a great tank is worth it. I am ordering some pinpoint solution tomorrow as well, just to confirm the settings of my at home tests. I will post the updates on here.

[spstimie]

http://www.simetric.co.uk/si_water.htm

of course this is all depends on temp. ro water works fine but it has to be 60 degrees to measure 1.000. so the medium is effective as long as you know the the requirements. if you dont then no medium is fully effective. and prepared vinegar is easier to try then measuring 161 ml of water.

[Zooid]

I have a 50ml syringe if you want to borrow it hehe.

[roadracn]

actually if you read most of the online documentation on this topic, RO actually measures less than 1.000 on our refrac's

[spstimie]

http://www.algone.com/salinity.php

"The hydrometer works on the principle that a solid body displaces its own weight of the liquid in which it floats. The hydrometer is calibrated at 60˚F (15.55˚C) in which distilled water equals 1.000 as the initial point. The readings will rise with increasing density of the water.

As the instrument is calibrated at a temperature of 60˚F (15.55˚C), it requires that the water to be tested will also have a temperature of 60˚F (15.55˚C) in order to get an accurate reading."

[TxOilman]

I made up a 1 liter calibration solution according to the recipe by Randy Holmes-Farley on his Reef Alchemy site. 2104 g RO/DI water plus 1/4 cup + 1 tsp of salt, for a salinity of 35. This solution gave a much different refractometer result (higher) than using 1 tsp + 161 ml. This makes sense because the smaller a recipe is broken down, the more error that is introduced.

[spstimie]

http://www.saltwaterfish.com/vb/showthread.php?t=49255

this is a good thread. just that if we are trying to calibrate a hydrometer/refractometer then we should take all factors into account. we need to know all the aspects. what temp is the instrument designed to be calibrated/used at? and what can we use to check it at what temperatures.

[roadracn]

TX I went off of the charts that the chemists made on another thread, and they checked both ways and came up with the same measurement, and also cross refrenced it with a known claibrated solution. It checked out. That being said, because I am a logic kinda guy, I am ordering 2 different pinpoint solutions to cross check it. Are you sure that you have everything correct? I agree that when shrinking a formula down that it does allow allow a margin of error, but Mathematically speaking you should be able to devide it equally and get an accurate measurement.

Here is the thread

http://archive.reefcentral.com/forum...readid=1283622

2ndly, I went to 60 deg as stated to calibrate the Refrac, and it has ATC from there, so I dont need to match the water that I am prepping for my waterchange to 60deg to do a check. The tool does it automatically. Also stated on the RC forums that I have read. Bottom line is that its not that complicated to make the solution, and check it to your refrac. I can't even refrence the people that I have talked to about this. They have forgotten more than I or most will ever know on this matter!

[roadracn]

TX for what its worth, I am willing to share some of my pinpoint so that you can check your DIY solution...let me know

[Ebmorri]

If you want to make the solution with smallest margin of error use a digital scale. Yes you maybe say +/- .75 gram or so unless you get a real good scale, so no matter the size of the sample you should be close. I used a scale to make my solution and what to check it with the pin point just to make sure, you know check, cross check, and check again.

[TxOilman]

This is a great thread. Of course, none of us have certified instruments for measurement of the calibration solution, so we all probably have some amount of error. I have a kitchen scale that measures in grams, and who knows how much error it has. Here's how analytical I got with the scale to check it - I took a stick of unopened butter in it's wrapper that is supposed to be 113 grams and my scale said it was 114 grams. Woo-hoo, it must be accurate!

I think Roadracn has the best idea - go out and buy a calibration solution. R - have you found a place locally to buy some or did you order thru the mail? I would take you up on your offer but I live up in Thornton.

[roadracn]

TX bought it online, shipped today. For my work I am all over the place so Thornton isnt that far off...

[TxOilman]

I work in Commerce City, so I'm there every day. At least that is closer than Thornton. Maybe I could meet you somewhere. I am also in on the invert order that Chris (Katyttt) handled, so will be driving to his place Thursday to pick up the new inhabitants. Were you part of that order too?