NTLabs - Marine Lab Magnesium (Mg) Test (35 Tests)

NTLabs – Marine Lab Magnesium (Mg) Test

Accurate Magnesium Testing for Reef Stability & Coral Health

Magnesium is a critical element in marine and reef aquariums, playing a central role in calcium utilisation, skeletal growth, and long-term chemical stability. The NTLabs Marine Lab Magnesium Test provides precise measurement of magnesium levels, allowing reef keepers to maintain the correct balance between magnesium, calcium, and KH for optimal coral and invertebrate health.

What Is Magnesium?

Magnesium is the second-most abundant cation in natural seawater and is essential for the efficient assimilation of calcium by marine invertebrates. Without sufficient magnesium, calcium becomes difficult for corals to utilise, limiting skeletal growth and overall reef development.

Why Test for Magnesium?

Correct magnesium levels allow calcium and carbonate ions to remain bioavailable, preventing premature precipitation and contributing to stable pH. As aquarium water ages, magnesium is gradually depleted through biological uptake and maintenance routines. Regular magnesium testing is therefore essential to maintain proper reef chemistry and prevent imbalances that affect calcium and KH stability.

Correct Magnesium Level

Natural seawater contains approximately 1300–1400 mg/l of magnesium.
Equally important is maintaining the correct magnesium-to-calcium ratio, which should be approximately 3:1 (magnesium to calcium). Deviations from this ratio often indicate broader chemical imbalance within the system.

What to Do If Magnesium Is Incorrect

• Perform partial water changes using a high-quality reef salt to restore magnesium levels

• Always test calcium and KH alongside magnesium, as all three parameters are closely linked

• If magnesium is incorrect, calcium and KH levels are likely also outside their optimal ranges

Key Features:

✅ Marine & Reef-Specific Magnesium Test (Mg²⁺)
✅ High-Precision Titration Method
✅ Clear Colour-Change Endpoint
✅ Professional-Grade Accuracy for Reef Systems
✅ Detailed Instructions Included

How to Test for Magnesium

1. Use the supplied 1 ml pipette to add 1 ml of aquarium water to the titration vessel

2. Add 10 drops of Mg-1 reagent — the sample will turn cloudy

3. Add 5 drops of Mg-2 reagent — the sample will turn pink

4. Attach the titration tip to the 1 ml syringe

5. Draw 1 ml of Mg-3 reagent into the syringe, ensuring the bottom of the plunger aligns with the 1.0 ml mark

   • A small air bubble below the plunger is normal and does not affect the test

6. Slowly dispense Mg-3 into the titration vessel while gently swirling

7. As the colour shifts from pink to purple, slow the dispensing rate

8. Stop the test when the solution turns blue with no hint of purple

9. Read the syringe at the bottom of the plunger and refer to the chart to determine magnesium concentration in mg/l (as Mg²⁺)

Important Testing Notes

To prevent cross-contamination:

• Do not return unused Mg-3 reagent from the syringe back into the bottle

• Rinse and dry the syringe, titration tip, and vessel with mineral-free water (RO water recommended) after each test

A critical testing tool for maintaining calcium efficiency, pH stability, and long-term success in marine and reef aquariums.