I have a 4x2x2 tank and basically i have a 20 something inch tube which has a pinky tinge and a 42 inch 40 watt power glo tube, ever after this my tank doesnt look very bright, or not as bright as i want it. Could it be because i have black sand as the substrate? because i know that black stuff absorbs light more and will gerenrally give a dark look. So is this lighting enough or do you reccomend i get more? If i need more then what do i need? Really need help here because i want to uprade two feet longer also so i want to be able to upgrade and keep my current lighting..