Dealing With Cyanobacteria

What must be the ugliest "problem" in a saltwater aquarium is cyanobacteria. Typically a velvety red blanket covering in worst case every surface in the tank. It suffocates the corals and drains the patience of the reefer.

In saltwater we deal with the nitrogen cycle which is the process of turning ammonia into nitrogen. When a tank is established there will be untraceable amounts of ammonia and nitrite, in my own tank it can be difficult to measure any nitrate as well since my refugium consumes any excess nitrate as well as phosphate. Because the macroalgae consume nitrates much faster than phosphate it is possible to get to a point where my refugium will deplete nitrates and then be unable to absorb any more phosphate. Now this is a problem if this process is out of balance because now phosphate readings will begin to climb while nitrates are very low.

Cyanobacteria can fix nitrogen gas and receive from this organic nitrogen's like ammonia and nitrates. To make matters worse for the reefer cyanobacteria is also photosynthetic drawing energy from light.
All in all this bacteria is very adept at surviving.

Now how do we go about getting rid of this stuff... Well, as with all things fishy there is a reason for this spreading in the first place. Some people add nitrates "in some form" to their tanks to make the macros absorb the phosphates without depleting nitrates. This will ensure that macroalgaes keep growing and out compete the cyanobacteria.
Most likely is excess nutrients caused by food and feces breaking down or dead livestock decaying. Naturally this means that you need to get in control of feedings. Overfeeding is feeding more than will be consumed by your fish in less than 3-5 minutes. If you only feed once per week but feed heavily that one time the guaranteed the majority of the food will not be eaten. I recommend smaller feedings once or twice per day depending on the type of fish.
A refugium is a great way to keep unwanted algae and bacteria at bay, the macroalgae growing in the refugium will consume the nutrients in the water column. When the reefer prunes the algae and throws it in the garbage he will physically remove these nutrients.

Finally there is a lot of ways to remove phosphates from the water using chemicals or phosphate sponges. I have little experience with these methods since I have always fought my cyanobacteria blooms with stricter feeding schedules, increased water changes and patience.