The lighting in the 40 vert is not as bright as I would like it to be. I have two hoods each with those spiral fluorescent bulbs. I'm not at home so can't say what wattage they are. The other tanks are lighted by 2 regular fluorescent 40 watt bulbs. The plants are overtaking the 20 long I have but I'm seeing yellowing of leaves. I think they are the older leaves. I do plan on changing over to T5's in the future.