Lighting does play a roll but, so does the current, you will see more colors appeare were there is water movement I even have it growing on the outlet from my filter, keep your calcium level around 450 thats what works best for me. If you could do a lighting upgrade it would help too, can you put a retro kit in your hood? If not build your self, you should have two light a daylight and a atinic, two 55 watt vho would be nice...cya