This a warning to all yes you can have too much light. I final purchased macro algae Gracilaria, green and red. I placed them in my sump with a plant 60wat bulb which is about 6" off surface. After a week and half I noticed tips turning white so replace bulb with 60wat daylight pig tail type bulb. But it was too late it tuned into mush and reduced to about 3rd of it size. Also the heat of the plant bulb was about three time that of the pig tail bulb.