replacement schedule for T5 & Flourscent lights

[ladyslipper]

Hi guys, would anyone tell me when they replace their T5 and/or fluorscent tubes? I have my plants under both and had thought I would replace them on a yearly basis. Should I do it on a more frequent or less frequent basis?

Also, in Canada, how do you dispose of spent light tubes? Do we have to take them any place special or just treat them as "regular" light bulbs?

Regards, mary