Taz - A Mag 7 is a great pump for the Berlin. I saw a huge difference when I upgraded my pump - the initial surge of foam nearly shot the lid off the skimmer. Increased skimming might help get rid of your cyano. I had a 6 month outbreak a little over a year ago in my 75 (have since upgraded to a 200). I did everything everyone suggested, lights out for 48 hours, reduced photo period, fed less, upgraded skimming, siphoned, more water changes than I can count, increased circulation, etc., etc., etc. That stuff had a real foothold and I was getting nowhere.
I finally resorted to Red Slime Remover and the problem disappeared - never to return. No adverse affects at all. I am not suggesting you use this product - just know that there is something on the market that is available if nothing else works. I don't advocate adding medications to the tank unless absolutely necessary, but if all else fails....
BTW, I am going through a pretty bad cyano outbreak in the 200. It is only 3 months old so I know this is part of the maturing process and therefore I am living with it and not worrrying about it. I have 2 queen conchs who are getting bigger by the day. I am NOT going to use Red Slime Remover in this situation because I am confident it will clear up in time. Again, it works but don't use it unless you absolutely have to.
