Have you beat Bryopsis with Kent Tech M?

[GoFish]

Wondering if anyone can share some more specifics on what they did to kill Bryopsis using Kent Tech M...
I have my Mg at 1800 and can still see it grow?? It's been at that level for 3 weeks. So either it doesn't work, or I'm doing something wrong. A couple months ago my Mg was at 1350. Went to the store and bought some Tech M, raised it to 1650 dosing twice daily for 3 days 50ppm per dose. After 3 weeks and still seeing it grow I trimmed one cluster of Bryopsis to use as an indicator. Then over the next 2 days raised it to its current level. Still nada, what's the deal. I actually have very little Bryopsis, just trying to kill it off before it spreads

Currently:
Nitrates 0
Phosphates 0.03
Lots of flow

Filtration:
Filter sock
Skimmer
Biopellets

I tried the first time in conjunction with GFO as per the local fish stores suggestion but noticed bleaching in a chalice so quickly removed it.