Lighting How Long Do CFLs Last?

[jawnroot]

I've searched high and low for an answer to this and have gotten all kinds of stuff ranging from "CFLs should be replaced after each grow" to "CFLs are usable for their entire rated life and lose at maximum 20% of their output." I've also read the PAR vs. lumen debate, with one side suggesting PAR degrades rapidly and as a result CFLs should be replaced after one or two grows.

Interestingly, this latter camp never really provides any useful evidence to back up the PAR degradation claims, no side by side grows with old and new bulbs. They just more or less state things matter of fact and that's the end of the convo.

Either way I'm curious. I don't like throwing things out (especially CFLs with Hg) and I try to get the most out of something that I can. For those of you with experience generally how long can you run your CFLs before yeild/growth begins to drop off significantly?

 

[namvet25]

Mine are going on two years and I don't see any neg affect to my grows.I do think I will change them soon because they probaly are loosing some efficiencey.Who ever told you change after every grow must have stock in the bulb company.:smokebuds:

 

[steelrat]

My light was rated for 8,000 hours and lasted 8,100.

Post about it here :

https://www.autoflower.org/f103/best-cfl-i-ever-used-four-ounces-dry-27319.html#post517900


steely

 

[Blissmesome]

I created a simple formula to help you with your question.

Lamp death time; 8000 hours.

Using a lamp to grow weed, 20 hours a day till lamp drop.. 8000/:20 = 400 days.
Keeping a chart nearby, Ted Swimson is growing weed for 75 days, 20 hours a day = 1500 hours.
By this math formula, Ted Swimson finished a successful grow in 75 days\1500h and he's lamp will last 6500h \ 325 more days.

You can divide total hour by usage hours (24,20,18,12) and get how much more days are left with this type of usage.