all part of a new setup. give the tank time to establish. algae comes in many forms and they all take nutrients from the water column. especially if it has nothing to compete with. you could reduce your light but if you alter anything else while the tank is cycling, you could disturb the establishment process. its best to just let nature run its course and wait it out. mine started on the front glass, then my driftwood and then all other surfaces of my glass. i think its cool to let it grow. when my cycle is done, i will moderately-heavily plant it. what algae still remains, will be controlled by otos and shrimp after the plants are established.