Ya... I wasn't sure how much to use... the bag said to use 50-200ml for every 25G of net volume. It was a 500 ml bag, so I used about half of it (I did it by weight).
I was on other sites and some have recommended running 750ml for a 100G tank using 3 Phosban 150s or one large 550...
It seems nothing is an exact science, so we'll trial and error with this amount...
