Help dosing Brightwell Magnesion-p

[GoFish]

Current mag is at 1200ppm, I've been dosing the maximum rate noted on the label (26ppm per day) however after 2 weeks (not every night) the level has remained the same... I spoke with someone at the LFS today and he mentioned i could raise the mag by 100 ppm per day (also suggested by another forum member) and that i could make a stock solution with 12 ounces of water and add "X"-number of grams of the Brightwell Magnesion-P (powder)

I've calculated water volume to be approx 48 gallons (taking into account sump, LR, etc...)

Desired level is around 1350ppm

My calculations tell me that i need to add 62.4 grams (this number doesn't sound like the same number the LFS gave me earlier... i thought he said something like 12 ounces or 1.2 ounces???)

Can someone with experience or time please help me figure out if this is accurate?

Please

Link to product page... http://brightwellaquatics.com/produc...npt.phphttp://