What Size Lights For 2ft Tank?

[Neal]

This might seem like a daft question, but what size tubes will I need for a 2ft/24" tank? Because if the tank is 2ft, and the lights are 2ft, they won't go together. What size would the tubes need to be?

Neal

 

[voo]

I have a 2ft tank and used 18" tubes.
I've just replaced the single bulb with an arcadia overtank luminaire, it's using 2x 18" bulbs