The Seachem Reef Advantage Calcium has other stuff in it, incl Mg and Sr, which maybe doesn't hold in mix as well. Just want to stress though, that the sediment/residue is very small, just enough that the last bit of liquid is not totally clear. And certainly not enough to be concerned about.

What I do like about this product, is that I never have to add Mg on its own. I test occasionally and it stays around 1400 - 1500, which is even on the high side.
http://www.seachem.com/Products/prod...dvCalcium.html

Oh ok I totally didn't interpret it that way but reading again I would have to agree with you my bad

Its all good.

I use BRS home mix bulk ingredients.
No sediment on the bottom of my mag/cal/alk jugs.
Although for the first week I did see separation (visible liquid density difference) inside one of them, but some shaking took care of that and hasn't come back.

No mixing, sometimes I get sediment but mostly the no mixing it because I am lazy, forgetful and my containers only hold 1 gallon which lasts just over a week for Ca and Alk (Mg lasts about 2.5-3 weeks).