I don't know anything about the tank but know at least a little about the rest, but you will need to supply a little more info. What kind of T5 is it - tubes, length, watts - Filter is a HOB or a canister and what size - doesn't matter much but what size type of heater is it - if it is a clamp on I would say that is a bad sign for the quality of the 'system'. Is all this stuff a generic Hagen - Hagen makes AquaClear, Fluval (and Laguna).
Bill