I have read and heard of people using the Excel and spot dosing when dosing their tank, meaning when you squirt the Excel in, squirt it onto the problem areas directly onto the algae. From what I have read about Excel, it is at least a mild algaecide, although I could be wrong about that.
I tried to grow Monte Carlo and the same thing happened to me, however, I couldn't actually reach it to spot dose it, so, maybe that could help? I also have a UV sterilizer and in my experience, that helps with the algae. I also have Nerite snails and (I know some people love them and some hate them) Siamese Algae eaters, amano shrimp and others that will help pick at the algae and keep it under control. I put in fish that will at least pick at the algae and I don't feed them too much so that they have to eat the algae. I, also, had a HUGE problem with algae and was going to give up until I got these fish, they cleaned it up in under a month.
I read that you cleaned off all of the green spot algae, I don't know exactly how you did that, but, taking out the rocks and boiling them in water will help to keep it from coming back for a little bit.
In my opinion, you will always have some algae, it's just a matter of not letting it get too bad that it takes over. I personally took out the monte carlo and gave up on it, I have never had too much luck with carpet plants and since I have a bunch of Cory's, I try not to keep any carpet plants so that they have room to swim around. You could also add Otto's, more Amano's and others that I am probably not thinking of. I am not sure how many fish you would want in the tank. I like a lot of fish. For green spot algae, I believe that Plecostomus will happily graze on it.
None of this is to bash you, these next ideas are just my personal beliefs. I never add Nitrogen, I personally feel that the fish produce enough of it to feed the plants, but, I guess that depends on how many fish you have in the tank and how big it is. I only use (again, nothing against people that do use other fertilizer than what I suggest, it is a personal choice) Flourish, Excel and some Iron. I have extremely hard water that gives most of the nutrients. I got an analysis done on my tap water. It saved me a lot of money on fertilizers that I don't need to add. Some people say that over dosing nutrients can cause algae and others say that that thinking is not true. I don't know which one it is, but, it at least saves me money on fertilizers that I don't need to add.
I hope this helps in some way. Algae can be a pain in the butt sometimes, but, imo it is a good indicator of the water quality. If it gets out of hand, you are doing something wrong, but, if it is kept at bay, then you are doing something right. Try not to get too frustrated, everyone deals with algae on some level. Your tank is absolutely gorgeous either way! Hopefully, I am not spreading any misinformation to you. I would double-check my (and others) suggestions on this.
Edit: I forgot to mention that I also have a CO2 injected, high-light aquarium. I am guessing from your specs that your aquarium is high-light as well. Last thought, if you are using Flourish and also Potassium, Iron and Nitrogen than you maybe double (or over) dosing. I don't have the bottles in front of me, but, i think that Flourish has nitrogen, iron and potassium in it. Just a thought, good luck!