Comments: I feel more confident now that I know my refractometer is calibrated correctly.

Comments: I'd been calibrating my refractometer with ro/di like the instructions on my refractometer said, and since my corals were looking a bit weird I figured I might as well try actual calibration fluid. When I tried it I found out that my refractometer has been reading .004 too high! Checked other refractometers and ALL of them were reading a minimum of .001 to .002 higher than they should have been, even though they were zeroed in with ro/di water. If you've been calibrating your refractometer with ro/di instead of calibration fluid then you're not getting accurate readings, this stuff is well worth the money.

Comments: Do yourself a favor and purchase this if you are using any type of refractometer. This solution is 35ppt and will help guarantee you are at the proper salinity levels.

Comments: Nice insurance for verifing the upper scale your refractometer. Zeroing your refractometer with distilled water doesn't insure its' accuracy at 1.0264.

Comments: Works as it supposed to.

Comments: I does its job. I use it to calibrate my refractometer, and there is enough to calibrate it many times. It is not on the product description, but it is 35ppt.

Comments: I highly recommend this product. Once you have calibrated the refractometer, you can double check with the solution. Or you can calibrate to the solution directly. Either way another means of confirmation. A must have product.

Comments: Like a lot of people I was using DI water to calibrate my refractometer. Being a lab tech by profession I was a little uneasy doing this. I found this calibration solution and figured why not give it a try and to my surprise my meter was off by 0.2% which is a lot with a reef tank. For around $10 you get enough to last you for years.

Comments: Knowing the accurate salinity is critical when raising marine larval fish. This product was excellent.

Comments: I ordered all the calibration fluids I could find to check my equipment. I discovered that my refractometer was about .003 high. I was measuring 1.026 and actual was about 1.022-1.023 - very frustrating. At least now I know. The temperature needing to be read is difficult to follow if your tank water is around 80 degrees and you keep this fluid at room temperature.

Comments: I calibrated my refractometer successfully with this solution. It gets the job done. It will take a long time to use all of this product. But when I do, I will buy more.

Comments: Used to setup refractometer, found it was off some. Bottle will last a million years when used for this.

Comments: American Marine makes good products at a good price. We tested the calibrating fluid in the university lab and it was right on.

Comments: Worked perfectly. It helped me calibrate my new refractometer. It turned out to be a little off.

Comments: Good stuff, it is easy to use and it works, what more can you ask for. I put mine in a clean, cry container so I can reuse it. You just need to make sure the probe is dry and not full of salt!
<br />Uncontaminated fluid can be reused many times.

Comments: Not provided, but calibrates at sg 1.026. Better to me than calibrating off of distilled. I store this in a ziplock after opening.

Comments: This fluid is a perfect measure of 35 PPT or 1.026 SG
<br />I used it to calibrate my marinedepot refractometer. Works well, better than using distilled water.

Comments: Simply put, it does what it's supposed to do. Although I agree with the other reviewer that they should label what the fluid is calibrated to, which is 35 ppt. That little bit of information isn't anywhere to be found on the label.

Comments: I use this product for calibrating my refractometer. Absolutely excellent and easy to use.

Comments: I bought the Pinpoint Salinity Calibration Fluid to fine tune my refractometer. After reading repeatedly that using pure water is not the best way to calibrate a refractometer, I decided to try this product. As many others have found (I read the Reefcentral forums), my refractometer was 3 thousandths off. So instead of 1.025, I was keeping my specific gravity closer to 1.022.
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<br />I had to do a little research to find out the salinity of the Pinpoint Salinity Calibration Fluid. I contacted American Marine Inc. and was told that it is 35ppt. It would have been nice if that information were on the bottle.

Comments: This product seem to work great. I used it to calibrate my refractometer and found that it was off a bit when I had calibrated it with RO water. This gives me some peace of mind that I am measuring relatively correctly.

Comments: I bought this product to confirm the calibration of my refractometer. Most refractometers have you calibrate with distilled water but this only lets you know that your refractometer is accurate at 0ppt/1.000 specific gravity. With this product you can now know with certainty that you saltwater ppt/specific gravity is correct.