Well some of the most common reason people have algae problems are simple things to fix. Here is a list of reasons why you could be having algae problems

The most common issue resulting in algae growth is a direct result of your fish tank placement. Never have your tank sitting in direct sunlight.

The norm for light length should be around 10-12 hours a day. For plants there are many other factors to take in to consideration.

Another of the most important factors to think about is your fishes food, and how much your giving them. You don't want to have a lot of it falling and rotting on your substrate.

Fourth, temperature, try to keep the tank a little on the cool side if possible. The high heat will allow for the algae to grow faster, so look at what temperature your tank is at if your having algae problems.

The last thing that you want to do to help rid the algae problem in your fish tank is to buy some kind of an algae eater. A pleco is good if you own a pond but other then that I wouldn't recommend getting one. They get to huge sizes of 2 feet or bigger, and can become aggressive towards other fish and plants as they get older. I would recommend a oto cat, or a Chinese algae eater. The Chinese algae eaters don't get much bigger then 5 inches, I think that it's more of a legend that they gt to 11''. But if your worried just get an oto cat.