Algae is normal in healthy tanks. It feeds on extra phosphates and nitrates in your tank water. The best way to control it's growth, is to remove and replace at least half the tank water every week. The more water you remove and the more often you remove it, the better. Water changes will remove the extra dissolved food in the water.
When you remove the water, plant or float some stem plants, like Water wisteria and Pennywort. These will feed on the phosphates and nitrates that aren't removed by the water change.
By removing it's food source, the algae will shrink and eventually disappear. I have planted tanks that have been running for several years and as the plants grew, the algae stopped growing. I have no visible algae in any of my planted tanks. But, I flush large amounts of pure, treated water through my tanks every 6 to 7 days.
"Fear not my child, just change the tank water."