Impurities in MgCl2 and MgSO4

[rt67ghy]

I recently got MgCl2 and MgSO4 to make my own Mg supplements and found certain impurities listed on the labels. Both products are by Merck KGaA Germany.

Impurities in MgCl2.6H2O:

1. Heavy metals (as Pb) <= 0.001 %
2. Al (Aluminum) <= 0.0001 %
3. As (Arsenic) <= 0.0002 %
4. Hg (Mercury) <= 0.0001 %
5. NH4 (Ammonium) <= 0.005 %
6. Pb (Lead) <= 0.0004 %
7. Br (Bromide) <= 0.05 %

Impurities in MgSO47H2O

1. Chlorides (Cl) <= 0.014 %
2. Heavy metals (as lead) <= 0.0005 %
3. As (Arsenic) <= 0.0002 %
4. Se (Selenic) <= 0.001 %

I have listed the elements which seem dangerous for marine inhabitants (especially corals) and not some others like potassium and calcium which are listed and are acceptable for marine life.

I'm planning to mix MgSO4 and MgCl2 in the ratio 3:5 and dose to keep Mg in tank in the range 1400 - 1450 mgL. Would any of these impurities be unacceptable in a marine tank at the concentrations that would be expected, or in the long run e.g. 10 yrs down the road would any of these elements build up and cause an issue?

 

[disc1]

Those are all at trace trace levels. I think you'll be fine. I doubt you'll find much better purity anywhere else.

 

[rt67ghy]

Thanks David. Appreciate it.