Can anyone advise me how much lighting do i need for a fiberglass tank (with 20mm glass frontage) of 2.4 m (l) x 1.2 m (d) x 1.0 m (h)? I am interested to get T5 tubes but not sure how long and how many of them i need?? This is for a tropical fish tank with no plants. Much appreciated if anyone have any ideas? Thanks.