Magnesium dosing

[thorsen]

With two part dosing why do we dose magnesium sulfate and magnesium chloride. What I understand is that the Mag sulfate builds up the sulfate levels over time so why not just dose Mag chloride?

[HighlandReefer]

When you use a two-part, you normally are using calcium chloride to raise your calcium level. If you use just Magnesium Chloride, then this may throw your chloride out of balance. To properly balance your sulfide and chloride, when using a two-part, you should mix your Mag. supplement at a ratio of 5 cups to 3 cups, magnesium chloride to magnesium sulfide by volume. ;)

[HighlandReefer]

This article written by Randy goes into more detail if you are interested:

An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System
http://reefkeeping.com/issues/2006-02/rhf/index.php

[TCU Reefer]

So what is the proper ratio?

I've read 5 cups and 3 cups for chloride to sulfate and I've also read 7.25 to .75.

Are both correct?

[HighlandReefer]

The proper ratios for volume (not weight) mixing a mag. supplement are:

1) If you are using a two-part (calcium chloride) then the ratio would be 5 cups to 3 cups (magnesium chloride to magnesium sulfate).

2) If you are using a kalk mix, calcium reactor or kalk reactor then the ratio would be 10 cups to 1 cup (magnesium chloride to magnesium sulfate).

3) If you are using a reactor and two-part, you will have to talk to Randy. ;)

[JAG107]

Would that be 5:3 cups for 1gal of freshwater?

[HighlandReefer]

Per Randy's article:

"Dissolve Epsom salts (3 cups) and magnesium chloride hexahydrate sold by the Dead Sea Works company (5 cups) in enough purified freshwater to make 1 gallon total volume. There will likely be a precipitate that forms even if you fully dissolve both ingredients separately. That precipitate is calcium sulfate (calcium as an impurity in the magnesium chloride and sulfate from the Epsom salts). It is fine and appropriate to dose the precipitate along with the remainder of the fluid by shaking it up before dosing."