[KevinK]

Originally Posted by Coleus

it does take a lots of Mg to bring your level to 1350. Use the reef calculator like this
http://reef.diesyst.com/flashcalc/flashcalc.html and see how much you need to dose to bring it to the desire level.

talking about a lot,

I gust broth mine up from 1200 to 1400 and used 24 cups in total (epson and dead sea)

so use the calculator as mentioned

sometimes buying bulk is better, as well as instant ocean is very low in mag, I always have to ad ad about 400 GRams of mag at eachwater change, gust to bring up the new salt mix