CHEMICLEAN!
There are hundreds if not thousands of species of cyano, the same species can respond differently to the same treatment in different tanks, your not doing your tank any favors by fighting a losing battle with toxic cyano.
Chemiclean it, get rid of it, work on your husbandry and upgrades, the cyano might return and it might not, there is probably a species of cyano that has evolved to live on MB7, you may have got your cyano on a frag or a piece of live rock or something, I'm sure that thousands of people have used chemiclean with no bad effects.
Stop worrying about what the reef police think, they don't know shit!
Cyano has been around for a billion years and you nor anybody else on this forum is going to wipe it out.