Replacement Tubes?

[tunagirll]

I have an Aqua One light for my 28 litre nano freshwater tank. It says it's 1 x 8W but there are two tubes in the light. They are T5.
 
How do I go about replacing these? They've been in for a year and ought to be replaced. Do I just pull them out and ask at the shop? If it says 1 x 8W, does that mean there are 2 x 4W in there or 2 x 8W?
 
Any help appreciated!

 

[Stimo]

so it doesn't say on the end of one of the bulbs?
1 x 8w i'd of said that would be just 1 x bulb

 

[KirkyArcher]

the only T5 AquaOne replacement lamps rated at 8w that I can find are these 12" items from Seapets

http/www.seapets.co.uk/products/aquarium-supplies/aquariums/aqua-one/aqua-one-shop/aqua-one-lighting/aqua-one-fluorescent-tube-tropical-8w-12in-t5.html

 

[tunagirll]

I'll pull one out and have a look. It's a tube