Marine Magnesium Test (Mg)
User manual
Understanding and controlling Magnesium levels
After calcium, magnesium is the second most important element in seawater for the growth of corals, as coral use both calcium and magnesium to build up their skeleton.
As a healthy coral is growing and thus in continuous need for magnesium, it is vital to measure and correct magnesium on a weekly basis.
We advise to keep magnesium levels between 1250 and 1300 mg/l.
General Guidelines
- Always take care that the test tube is clean before use.
- Clean the tube directly after use.
- Take the volume of the water sample as precisely as possible.
- Keep the drop bottle perfectly vertical during dropping.
- Take care that no air bubbles are included in the drops.
Test procedure:
- Take a water sample of 2 ml.
- Add 5 drops of Mg-1 fluid and shake the tube for 20 seconds.
- Add 5 drops of Mg-2 fluid and shake the test tube; the water sample becomes dark red – red purple of colour.
- Mount the plastic tip onto the 1 ml syringe and fill the syringe with Mg-3 test fluid. Above the fluid an air bubble will appear, this is normal. The air compensates for the volume in the tip. Add the fluid slowly until the sample colours blue.
- Multiply the volume of test fluid (in ml) required to change the colour from red/purple to blue by 1,500 to determine the magnesium content. (E.g. 0,8 ml needed to convert from Red / Purple to Blue = 0,8 x 1.500 = 1.200 mg Magnesium per litre).
Alternatively, use the chart below.
Test procedure:
- Take a water sample of 2 ml.
- Add 5 drops of Mg-1 fluid and shake the tube for 20 seconds.
- Add 5 drops of Mg-2 fluid and shake the test tube; the water sample becomes dark red – red purple of colour.
- Mount the plastic tip onto the 1 ml syringe and fill the syringe with Mg-3 test fluid. Above the fluid an air bubble will appear, this is normal. The air compensates for the volume in the tip. Add the fluid slowly until the sample colours blue.
- Multiply the volume of test fluid (in ml) required to change the colour from red/purple to blue by 1,500 to determine the magnesium content. (E.g. 0,8 ml needed to convert from Red / Purple to Blue = 0,8 x 1.500 = 1.200 mg Magnesium per litre).
Alternatively, use the chart below.
