>Yeh, I have the two pumps but as I indicated.. I found Red Sea "MAG" MgCl in Danvers Hardware which will not add the sulfates!
So I tossed my Epsom salts<
Well....there's a little more to this, chemistry wise. If you are using Randy's two part method your Mg will drop as mentioned above. Randy's 'two part' also includes the addition of Epsom salts (MgSO4). With Randy's system the chloride builds up over time, and the addition of MgSO4 helps to control the loss of Mg, and off set the build up of chloride with a buildup in sulfate (SO4). Trouble is, since Randy's system only uses MgSO4 the sulfate builds up too quickly. Randy knew this but figured people could do simple water changes to control, which is true on small to moderate sized tanks. The reason he did not include MgCl2 in the magnesium supplement is that he could not find an inexpensive easily obtainable source for MgCl2. We did a group buy on a very high quality MgCl2, and it's possible that the stuff available from Home Depot (I have seen it) is of a similar quality, but then it might not be. I've had long discussions about this with folks. This is ice melt MAG, and they are not likely very careful about transport and contaminants, then again, maybe they are.
Back to my concern about you tossing your Epsom salts:
If you start using ONLY MgCl2 then you will actually get too high in chloride.......SO......the best method if you are using Randy's system is to used a different ratio of MgCl2 to MgSO4 that you would use if you were looking to JUST adjust the magnesium level in a tank that was not using his system.
All of the details about this are in the thread in the group buy forum about the MgCl2 group buy we did, but I will post the details below as well.
http://216.235.242.50/forums/showthread.php?t=3568&page=1&pp=40&highlight=magnesium
With a tank using Randy's two part method use this receipe:
865 grams MgSO4.7H20 (Epsom salts)
730 grams MgCl2.6H20
plus water to a total volume of 1 gallon
If you are looking to JUST supplement magnesium then use this receipe:
664 grams MgCl2.6H2O
113 grams MgSO4.7H2O (Epsom salts, from the drug store costs $1.99 for 3 lbs)
plus enough DI water to make 1 gallon.