The new Elos Magnesium AquaTest is advertised as providing precise measurement of the magnesium level in aquarium water. The Elos Magnesium test is designed to have “real color” technology which assists in the reading of the kit. In the past I have used, and been quite happy with the Salifert range of tests, including the magnesium kit.
However, I am often unsure with salifert where the actual color change occurs in that system- at least to within a few drops. In addition, many people seem unsure how to read the syringe based calibration of the salifert system. So with the years of experience of other kits under my belt I was interested to see how the Elos magnesium test performed.
First impressions of the packaging are a pretty neat design, simple and easy to follow instructions with nicely packaged components. The Elos test, unlike the Salifert, is a two part test. In part A, a 3 ml water sample is titrated with Reagent A. This is added drop wise until the orange color transitions to green.
The user counts the drops until this change. I have to admit I was skeptical of the color change and expected it to extend over several drops. I was, however, very pleasantly surprised to see the color go from the vibrant orange to bottle green in the space of a single drop. Absolutely no ambiguity at all.
The photograph labeled Part A shows the difference before and after a single drop of reagent. During Part B, a 3 ml sample is treated with 5 drops of reagent B and a small scoop of powder. The resulting solution is cloudy pink.
This is titrated drop wise with reagent D until a blue coloration is achieved. Once again this happens between one drop and the next. Again, no ambiguity at all. The colors are shown in the photo labeled Part B.
To determine the Mg concentration the number of drops in Part B are subtracted from the number of drops in Part A (in my case 5 drops subtracted from 30 drops), and then this value is multiplied by 50 ( so my magnesium level was 25×50= 1250 mg/L – which is the same as ppm). I repeated this test several times and obtained the same result each time. Independent test with the salifert system gave approximately the same answer- within the ambiguity of that system.
Overall, a very simple and easy to use test kit. The accuracy is to within 50mg/L (50ppm). The color changes live up to the reputation of “real color”, and even the most poorly sighted aquarist should have no trouble interpreting the color change. Counting drops is simple, and the math is very easy to perform. All in all an excellent and easy to use kit. The Test kit price is approximately $25.
Now I need go supplement my tanks back to the 1330mg/L I normally maintain in my system.