Aquarium Light Ballast

[Nick16]

hi, i want to stick another light tube in my tank, either a t5 or t8 but i dont know which. i would rather have a t5 because its brighter and smaller. All i want is the tube which i can easily get and the end caps that are joined to all the wires that then plugs in. im really confused about the whole lighting thing! but i found a ballast for the 39w t5 and it was £55!!!!
is that how much they are normally?? does anyone know if there is a cheaper alternative!! Help needed

 

[Nick16]

anyone? some one must know about these things! all i want to do is attach another light tube! i dont care if its t8 or t5. as long as its around 800-900mm and 30w or more. has anyone else do this? where did u get all of the stuff needed?