How to test magnesium levels in a reef tank

With the larger syringe, put 2mL of tank water into the vile.

Add 5 drops of Mg-1 to the vile with the tank water. Swirl it together.

Next add one spoonful of the Mg-2 powder to the vile. Swirl to combine.

It should turn pink like this.

Place the pink tip firmly on the smaller syringe.

Suck up the Mg-3 liquid until the plunger is at the 1mL line. There will be some air, this is okay.

Add drops to the vile and swirl to combine.

Keep adding drops and swirling until the liquid in the vile turns blue like this. Look at where the end of the plunger is and make a note of that number.

Now use the chart included with the test kit and the number from the previous step to find the ppm concentration of magnesium. Natural sea water is around 1300 ppm.