For those who are dosing

[Rodolfo Garcia]

Are yall needing to dose magnesium? I have to dose calcium and kh everyday from bulk reef supply but my magnesium stays consistently at around 1450 without needing to dose. Is this normal?

 

[Randy Holmes-Farley Verified Community Expert]

Magnesium never depletes faster than 1/10th as fast as calcium. Thus, depending on the calcium dose and possible water changes, magnesium may not be needed.

I recommend dosing it based on alk or calcium demand, not on measurement.

https://www.reef2reef.com/threads/just-say-no-to-magnesium-testing-rmm-is-born.1017528/

 

[Rodolfo Garcia]

Magnesium never depletes faster than 1/10th as fast as calcium. Thus, depending on the calcium dose and possible water changes, magnesium may not be needed.

I recommend dosing it based on alk or calcium demand, not on measurement.

https://www.reef2reef.com/threads/just-say-no-to-magnesium-testing-rmm-is-born.1017528/

Thank you for your response Randy. I looked over the thread that you linked and it’s very informative. Regarding rule 3 of your thread, you say to add magnesium at 5% to 10% of the total amount of calcium. Daily i add 60ml of calcium 2 part from BRS, does this mean i would add around 3 to 6 ml of magnesium? Does your rule apply to this as well?

 

[Randy Holmes-Farley Verified Community Expert]

Thank you for your response Randy. I looked over the thread that you linked and it’s very informative. Regarding rule 3 of your thread, you say to add magnesium at 5% to 10% of the total amount of calcium. Daily i add 60ml of calcium 2 part from BRS, does this mean i would add around 3 to 6 ml of magnesium? Does your rule apply to this as well?

The 5-10% is by ppm dosed, not by the mL of dosing solutions, which can vary in concentration.

Use this calculator to determine the ppm of calcium you are dosing, take 1/10th to 1/20th of that as the magnesium dose, and use the same calculator to get a volume. Use the entries for Randy’s recipe #1, which is what BRS uses.

https://reef.diesyst.com/chemcalc/chem_calc3.html