I wasn't too scientific about it. In my ~60 gallon system, I dosed 45 ml twice per day. A couple times early on I did it threee times per day. At day 6 when I noticed the bryopsis not growing so well, I used a turkey baster and it blew right of the rocks. I dosed a couple more times and then stopped.
I will test the water this weekend and let you know what I ended up at. Although I changed 10% this morning when I noticed things looking a little down.
I think the suggested target is something like 1800 ppm.
BTW- Tom why isn't your sig working? Did you try to upload it to CR?