cant get my mag up

[fragaholic]

Tanks been set up for about 2-3 weeks. I filled it using kent salt and the mag was at about 1000 ppm. I used an open bottle which had about 3/4 left of kent tech-M in attemp to raise the mag. used that bottle and got it to about 1120 ppm. got another $11.00 bottle of the stuff and used the entire thing and my mag is still only at 1280. I cant afford to keep buying bottles of this stuff, anyone got any ideas on what else i can do to try to raise the mag in my tank? Something cheaper?

-Thanks

[sammiefish]

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

Epsom Salts