I have what I'm told medium light on my 75G right now with one 48" 40 watt 6500 bulb with a reflector. Also on this tank is the Marineland double bright light with 16 LED watts. The plants are doing well but I think the green Tiger Lotus should do better. Is there a safe and not too expensive way to add light without needing to add Co2? I do dose with Excel and Fluorish.