When to change T5 bulbs?

UDGags

Lifetime Charter Member
Lifetime Member
Sep 13, 2009
630
38
28
43
Kettering, Ohio, United States
Simple question....

How do you know it's time to change your T5 bulbs?


I'm running ATI dimmable units and was trying to figure out how I should know that the bulbs need changed. PAR is still good but I can't measure the spectrum, which is what I'm thinking goes first. Is there a scientific/engineering method that works? (Not really looking for an answer like "I change every 6 months")
 

Tom Barr

Founder
Staff member
Administrator
Jan 23, 2005
18,699
786
113
When they burn out or flicker and die?

Most shifts run Blue, higher energy shorter wave lengths to red orange shifts over time, most bulbs trend this way.
So plants would be fine either way. Maybe change the blue/white colors only.
Maybe once every 2 years for fun.
I do not.
 

Tom Barr

Founder
Staff member
Administrator
Jan 23, 2005
18,699
786
113
When they burn out or flicker and die?

Most shifts run Blue, higher energy shorter wave lengths to red orange shifts over time, most bulbs trend this way.
So plants would be fine either way. Maybe change the blue/white colors only.
Maybe once every 2 years for fun.
I do not.
 

Yo-han

Guru Class Expert
Feb 6, 2011
285
0
16
Netherlands
I think the chart below is quite true. After 20.000 hours, the bulbs will start to die faster. Loosing about 15% of power in the first 20.000 hours. Not sure whether dimming them would make them last longer or shorter, but lets say the same. Than with 10 hours a day, it should last 2000 days (6 years!) You want it to be above 95% of its max power, than 2500 hours (250 days)

LumenMaintenanceChart.jpg


LumenMaintenanceChart.jpg
 

UDGags

Lifetime Charter Member
Lifetime Member
Sep 13, 2009
630
38
28
43
Kettering, Ohio, United States
I'm going on a year of use so ~3000hrs of my current bulbs and have another set ready to put in but wasn't sure when to do it. I know my PAR rating was slightly lower but I just increased the dimmer% to compensate for it on the ATI unit.


You want it to be above 95% of its max power, than 2500 hours (250 days)

Why do you want it to be above 95%? power?