T5 versus T8

[Smalleyboy]

I currently have a Juwel Rio 300 complete with the standard 2 x 38W tubes which I believe are T8. Arcadia have a product called the I-Bar range which replaces the Juwel lighting system with either T5 or T8 tubes. The T5 unit I am considering buying has 2 x 39W tubes.

On the face of it, this only looks like an overall increase of 1W per tube, but I'm sure that T5 tubes are significantly brighter than T8 tubes.

Does anybody know how to correctly compare the outputs between T5 and T8?

 

[Silly me]

what I do know is that T8 and T12 tubes only hold there power 6-12 months but T5 tubes can last for as long as 3 years..

 

[Smalleyboy]

I may have got it wrong and my tank maybe came with T12 and therefore I would change to T8 Arcadia tubes but they still have an output the same as my existing tubes.

 

[andywg]

The T number only refers to the diameter of the tube in eigths of an inch.

The reason T5s are often more powerful is because they are Very High Output (VHO) flourescents and thus put more power out.

 

[Silly me]

T5 tubes also need a different starter unit to run..