Salifert Magnesium Mg profi test

Magnesium is an important major element in seawater and helps stabilise the relationship between calcium and alkalinity. An insufficient magnesium concentration may make it difficult to maintain appropriate calcium and alkalinity values because calcium carbonate can precipitate more readily.

The Salifert test uses an indicator and liquid titration reagent. Reagent is added to a measured seawater sample until the colour changes to grey or blue. The remaining reagent in the syringe is then converted into a magnesium result using the supplied table.

Key features

• Magnesium test for marine aquariums
• Suitable for reef aquariums
• Measurement range up to approximately 1,500 mg/l
• Approximate resolution: 30 mg/l
• Clear grey or blue endpoint
• Titration-based procedure
• Useful for monitoring magnesium supplementation
• Suitable for Balling systems and calcium-reactor monitoring
• Suitable for checking newly mixed saltwater
• Calcium and strontium do not normally interfere at combined concentrations of 300–500 mg/l
• Approximately 50 tests
• No electronic meter or batteries required
• Marine water only

Technical information

• Product: Salifert Magnesium Mg Profi Test
• Test type: colour-change titration test
• Parameter: magnesium Mg
• Units: mg/l or ppm
• Range: up to approximately 1,500 mg/l
• Approximate resolution: 30 mg/l
• Sample volume in the current version: generally 2 ml
• Number of tests: approximately 50
• Water type: marine water only
• Electronic meter required: no

Directions

Different versions of the Salifert magnesium test exist. Always follow the instructions supplied with the individual package.

For the common 2 ml version:

1. Add 2 ml of marine water to the test vial.
2. Add the specified amount of Mg-1 indicator.
3. Add the powdered reagent if included in the kit version.
4. Attach the plastic tip to the 1 ml titration syringe.
5. Draw titration reagent to the 1.00 ml mark.
6. Do not remove the normal air space inside the syringe tip.
7. Add titration reagent gradually while swirling.
8. Near the endpoint, add the reagent drop by drop.
9. Stop when the colour changes clearly to grey or blue.
10. Hold the syringe with the tip upward.
11. Read the remaining reagent.
12. Determine magnesium from the supplied table.

For the applicable 2 ml version, the result may also be calculated as:

Magnesium mg/l = (1 − syringe reading) × 1500