• I need advice on the salinity of a marine aquarium.

  • Carrie1606

I can't understand what to believe and how to proceed. About a month ago, I bought a refractometer from Tum; before that, I measured with a Sera float and an Aquamedic Control Digital device. Now I have a dilemma about which one is showing the correct readings: the refractometer or my old devices. I have calibrated the refractometer in every possible way, and it shows a salinity of 1.036-1.037, while the old devices show 1.022-1.023. Today, I also bought an Aquamedic float, and it shows 1.021. What should I do?

Erica

It would make sense to ask someone for a reliable refractometer and compare the readings.

Courtney

Check the float readings in distilled water or in water after osmosis. My float underestimates the readings by 0.002. In osmosis, it shows 0.998. (If I didn't make a mistake with the digits after the decimal point)

Catherine

I encountered the same dilemma... the refractometer turned out to be a delicate device - I calibrated it before each measurement - then switched purely to a float - when I was using the refractometer, I added water to the freshwater - I noticed inconsistencies with the readings... in fact, I added salt by 5-6 units in the negative.

Noah1632

I have been using a refractometer for a year and a half - it always shows accurately, and I also have a float.

Linda

I have also been using a refractometer for about two years without any problems, and I also have an Aquamedic float just in case. I didn't buy it from Igor; here is its photo. Here are the links for the setup.

Todd

You intrigued me, so I took my refractometer and checked the calibration with reverse osmosis. It turned out I was underestimating by about 2-3 divisions; I measured the water and it showed 1.028. I calibrated it more than 9 months ago.

Jacob7201

Remember that the hydrometer is calibrated at a specific temperature; for accurate measurements, there are temperature compensation tables. By the way, does anyone have a table for AC-OH-5 at 20 degrees Celsius, 1000-1080?