Raising Mg

[Ruth]

Heya Mark I use the Seachem stuff as well but don't bother going through all the calculation like you do. I know that you do have to use quite a bit though when you are raising it that much. What I do is mix about 3 tblsp. at a time in some tank water to dissolve and then add it to my sump. Test the next day - see where I am at as far as mg. level goes and just keep repeating the process every day until I am at where I want to be. I have never had to raise it that much but to raise it even 100 points takes me about a week to do. I find that this is a good way to monitor and not go too quickly. Besides with a bunch of live rock in there I am never sure of what my exact water volume is.

[Beverly]

Mark, when measuring the size of your tank, measure the inside of your tank, not the outside. Makes a big difference sometimes in the total volume. Then use the Aquarium System Volume Calculator to calculate real volume. I think the calculator adjusts for rock volume as well. There is also a place to add in the volume of your sump:

http://home.comcast.net/~jdieck1/volcalc.html

Once you have the right volume, use the Reef Chemistry Calculator to double check your calculations. I don't use Seachem products, but Seachem's Mg products are listed in this calculator. When my Mg gets low, but never as low as your levels, I have to add a whole whack of of Kent's product:

http://home.comcast.net/~jdieck1/chem_calc3.html