grow lights - expiration dates?

[weebleswobble]

today i read an internet article saying that grow light bulbs/florescent light bulbs should be replaced every *TWO* years

Comments

[dark_phoenix54]

The tubes go way down in the amount of light they put out pretty quickly. The human eye can't detect it, but the plants can end up leggier. How many years they last depends on how many hours you use them per year, of course. If you only use them a short time before moving the plants outside, they're going to last more than 2 years, but at 5 years I'd definitely change them.

[fiddlingfrog]

Seconding this: it's not the time since you bought the tube that counts, it's the hours you've used it that matters. What happens is that as the lamp is being used, the cathodes at either end of the tube burn off. Most of the atoms resettle on the cathode at the other end of the tube, but some will deposit on the phosphor coating itself, gradually causing the tube to darken.

[weebleswobble]

thanks. i didnt think about them only being used a couple months a year.

[weebleswobble]

thanks for explaining. and yes i only use them about 3 months a year.

[helenatroy]

I think that recommendation is there to make you buy a new growlight after two years (probably because they couldn't figure out how to make one that would crap out in that period of time. sorry, that's the cynic in me talking) If your plants are growing nicely, I think it's fine.

[weebleswobble]

thanks. it was pointed out that my bulbs might last longer because i only use them a few months a year. that makes sense to me, since things seem to still be growing well.

[beesandbrews]

I read similar advice regarding aquarium lighting for plants. Over time the spectrum emitted changes. Like most things, I suspect it's a YMMV situation. The more hours on the tube, the more wear. If you only use the grow lights for a short time each year you probably will get more effective years out of them then someone who starts plants year round.

[weebleswobble]

thanks, and yes i only use them for about 3 months a year.

[jaxita]

Same idea with basking lighting for turtles. Only I was told to replace the one in my turtles' tank every six months, so every two years is nothing by comparison.

[weebleswobble]

every six months! wow!