Ok so I'm starting to get my tank set up to be heavily planted, one problem.... my lighting. I have around a 15 gallon tank (24"x12"x12"), I have 1 15 watt bulb and another on the way which would make a total of 30 watts... which would only be around 2wpg im looking for around 3-4 wpg but have no more room to place lighting... Can anyone help me out with this 1?