Calcium and Magnesium Relationship

[PharmrJohn]

I have a question. I thought I read somewhere that Magnesium is utilized at one-tenth the rate of Calcium. Is this why we have Calcium Reactors? To keep up with the minimal use of Mag and maintain the balance? Sorry if this a stupid question. I'm just trying to get a hold of the utilization and ultimate replenishment of both.

 

[Lavey29]

Magnesium is the buffer for alk and calcium. A calcium reactor is just another method for maintaining alk, calcium and some trace elements in a tank. It does not raise salinity like some 2 part dosing does. Calcium reactor works well on larger systems with a lot of stony corals. Yes Magnesium depletes at roughly 1/10th rate of alk and calcium.

 

[Uncle99]

I maintain them separately, a reactor is just one way of adding back CA, I just dose CA directly to 450ppm and my MG dose runs 1/6th of the CA dose.

But that would vary a bit between products I think and how high you maintain MG.

Great question!

 

[PharmrJohn]

Magnesium is the buffer for alk and calcium. A calcium reactor is just another method for maintaining alk, calcium and some trace elements in a tank. It does not raise salinity like some 2 part dosing does. Calcium reactor works well on larger systems with a lot of stony corals. Yes Magnesium depletes at roughly 1/10th rate of alk and calcium.

So there is a 1:1 ratio in the depletion of Calcium and ALK? They both are depleted at the same rate? And I have always thought that ALK was the buffer.....

 

[Lavey29]

So there is a 1:1 ratio in the depletion of Calcium and ALK? They both are depleted at the same rate? And I have always thought that ALK was the buffer.....

Generally alk and cal deplete in similar proportion but not always. I dose the same amount of alk and cal daily which is 40ml of each. I only dose 15ml of magnesium once a week by hand. Typically water changes cover all the magnesium requirements.

 

[PharmrJohn]

Excellent. Thank you all so much for answering my query. Much appreciated.

 

[Lavey29]

Excellent. Thank you all so much for answering my query. Much appreciated.

The best way to determine initial dosing needs is via alk consumption. Measure alk at the same time for 3 consecutive days and that will give you a baseline for alk consumption. You can start with this for alk and cal dosing needs and make adjustments as needed.