Refractometer Calibration Standard, Accurate Reference for The Calibration of Seawater Refractometers, Hydrometers & Other Density Measuring Equipment, RES60

works as needed.

Advertised as 35 PPT and it was spy on, verified against 4 refractometers and 3 electronic readers. Brighter ll is always as advertised, unlike a few competitors that can be all over the map

I used this product and it proved the solution I had for years had gone bad. My old solution was off by .004. Despite properly shaking both old and new solutions the refractometer was off by a specific gravity of .004. I read 1.021 on my old solution and 1.025 with my new solution. This product states to replace your solution after time. They are right to recommend this. Also, for newbies...remember the 35 ppt Salinity = 1.0264 on your specific gravity. The left side of you refractometer is for specific gravity, the right side is the reading you set to 35 after 45 seconds.InstructionsShake product well before using.Clean Refractometer prism slide with fresh distilled water.Dry completely with soft clean dry cloth.Place several drops of Brightwell Refractometer Calibration Standard fluid on the slide.Wait 45 seconds and calibrate to 35 ppt Salinity.

Took weeks to arrive and when it finally did it was leaking in the sealed bag it arrived in. Amazon was quick to refund me without having to return. Thank you Amazon. There was a usable amount left in the bottle so I wanted to try it out. I had calibrated using distilled water before but wanted to make sure my tool was accurate so I bought this. Half cup sea salt to one cup of water normally gets me pretty close to 35 parts per thousand and that's what my refractive meter shows after being calibrated with distilled. This stuff is reading 76 or 77 parts for thousand salinity so it's dangerously and comically incorrect. All I can say is wow. If this is what I use to calibrate my tool in the beginning I would have been in a world of hurt. Luckily it's so far off that it wouldn't have gone unnoticed.

I bought this product as I was about to run out of the acurasea that I had previously been using and I couldn't get more of that brand, I was shocked when I put this on my refractometer and it read as 1.030. I had a feeling this wasn't right and after searching sone forums I found I wasn't the only person to have this issue.To be sure that it wasn't the old solution I did a few things to check, I tested the old solution to check it definitely read correct, I tested my tank to see what that read, I tested my tank with a hydrometer which although not perfect read as expected and I made my own solution to test. I then put all three of these into a hydrometer and that said the brightwell was also wrong compared to the others. All of these test showed me that the product infact reads wrong and doesn't calibrate a refractometer properly.I would stay well away from this product, it will make you think all of your equipment is faulty and doubt everything you use to test. My advice is to either get acurasea that I know to be accurate or do some googling and make your own solution. It will save you alot of confusion and work.