The T5 version of the Super Tropical Pink tube. T5 is the narrower 16mm format and puts out considerably more light per centimetre than T8, which is why a planted tank that will not grow anything under T8 often will under T5. More light is not automatically better though — over a lightly planted tank a high-output fitting grows algae rather than plants.
Sizes
- 212mm — 6w
- 288mm — 8w
- 397mm — 16w
- 550mm — 24w
- 850mm — 39w
- 1150mm — 54w
Match the wattage, not only the length. The tube has to suit the ballast or transformer already in the fitting, and length alone will not tell you that — read the wattage printed on the tube you are taking out.
Replace them about once a year. Fluorescent output and colour shift long before a tube actually fails. One that still lights can be doing well under half the work it did when new, and plants notice before you do.
Run the light on a timer. Six to eight hours a day is a sensible starting point, and consistency matters more than duration.