How often do you change your lightbulbs?

[taralm13]

I checked and what I have is one 24 watt 10k daylight bulb (it is pink) and one 24 watt T5HO bulb. Here is a link to the light I bought http://www.petmountain.com/product/...-10k-daylight-1x24-watt-freshwater-t5ho-.html

I already bought replacement bulbs to have on hand for when I need to change them. I just don't know when I should do it. I think I started using the light sometime around November - December of last year. I leave my lights on every day for 10 hours if this matters.

 

[jmhart]

when my PAR meter tells me too.


I've got bulbs that are 18 months old and just now starting to wane.

 

[Canuck]

I use PCs. I change them when they blow out.