This is such a complicated situation i'm not sure where to start. There are several things at play here. Before we go on, I also want to caution you when it comes to dealing with an LFS. There are good ones out there, no doubt, but the large majority of LFS do not have employees who have enough experience with saltwater systems to help you properly.
There have also been some mistakes made with your system, which it sounds like came under the guidance of this LFS. You added your live stock WAY to fast. I mean WAY fast. Your system has to have time to mature. This isn't a freshwater tank. Testing for Ammonia and Nitrite, and calling a tank "cycled" when they both reach zero... this is not a method to consider on a saltwater system. Obviously, ammonia and nitrite need to reach zero, but this is not the "test" of stability that we need to feel confident. Having patience and allowing a tank to mature is critical. What I find most frustrating is the inclusion of an anemone in a tank this young. It is down right irresponsible for anyone to suggest you make that purchase. It makes me furious to hear about these situations.
There are a gazillion links on google which discuss cynobacteria. With an aquarium only 2 months old, cyno is not uncommon, and is almost predictable. We don't have to go into a lot of depth. But here are a few points to consider. When dealing with cyno you have to look for places where your system is not in balance and for places where excess nutrients are being introduced. Here are a few tips:
1 - make sure your system is set up properly. If you have a sand bed, it needs to be an extremely thin layer, or should be a minimum of 4'' in depth. Anything inbetween tends to result in nutrient buildups leaching into the aquarium. This is more of a long term issue than short term.
What type of filtration are you using? Using any type of man made biological filter on a reef system will result in nutrient buildup. You want to rely on the live rock and a good protein skimmer as your only methods of filtration.
2 - Do you have filter pads? If so, they must be cleaned daily. This includes sponge filter outputs on a protein skimmer, as well as filter pads inside of a canister filter (which I wouldn't use on a reef). Filter pads accumulate organic particles which need to be removed from the system before they become biologically active, resulting in nutrient input.
3 - Water flow, water flow, water flow. You need to be turning that tank over 20-30 times per hour at minimum. Sometimes increasing water flow alone is enough to prevent the spreading of cyno. In a 30 gallon tank, i would run 3 power heads in addition to your skimmer. Place the powerheads at different levels within the water column and angle them in such a way to prevent dead spots.
4 - Test for alkalinity and calcium. Dose supplements as needed to maintain your alkalinity between 8 and 14 DKH and calcium between 400ppm and 500ppm. Normally one of these levels will be on the upper end of this scale and the other will be on the lower end. This step is critical to allowing coraline algae to grow. After coraline takes hold, it is very difficult for the cyno to spread. (During a cyno outbreak, i would suggest keeping alkalinity at the higher end of the recommendation, say 12 to 14 DKH, especially for systems that have difficulty pushing calcium above 420ppm.)
This bullet point is so important that I almost skipped everything else and only discussed the relationship between alkalinity and calcium and how important they are to overall tank stability. If you are not testing for both Alkalinity and Calcium, you are going to struggle long term. Folks, this applies to fish only systems as well!!
As i mentioned, this is complicated. Cyno outbreaks are best avoided by being extremely patience and allowing your system multiple opportunities to mature as you add livestock. My current reef is only 6 months old and I have less livestock than you have. You should never add further livestock unless the current livestock and overall system is showing great signs of success. Even then, more sensitive selections, or selections which feed on copepod and amphipod populations, should be avoided for the first several months.