Light question

jmsieglaff · March 9, 2015

I have a grow light for starting seeds with a high output 4' T5 6500K 54W light bulb (not sure of lumens off hand). I have an extra 4' shop light with slots for two bulbs, so I thought I'd rig it up for some extra lights on my seedlings (never a bad idea to have more light, right?)

I bought two daylight 6500K 4' T12 bulbs (at least that is what the cardboard sleeve said): (e.g. http://www.amazon.com/Sylvania-24477.../dp/B000BO5A1Y)

Color/Finish: Daylight
Color Temperature: 6,500K
Average Lifetime: 20000 hours
Lumens (light output): 2180
CRI: 88

But when I took them out of the cardboard sleeve, one of them was actually a 3400K 4' T12 aquarium/terraium/grow bulb (e.g. http://www.amazon.com/Sylvania-24671.../dp/B000M2TX22)

Color Temperature: 3,400K
Average Lifetime: 20000 hours
Lumens (light output): 1700
CRI: 89

At first I wasn't pleased, but then I thought the mix of 6500K light and 3400K light might not be a bad thing. Any thoughts on these two bulbs for seedlings? Compared to just two 6500K bulbs?

March 9, 2015	#1
jmsieglaff Tomatovillian™ Join Date: Jan 2014 Location: Southern WI Posts: 2,742	Light question I have a grow light for starting seeds with a high output 4' T5 6500K 54W light bulb (not sure of lumens off hand). I have an extra 4' shop light with slots for two bulbs, so I thought I'd rig it up for some extra lights on my seedlings (never a bad idea to have more light, right?) I bought two daylight 6500K 4' T12 bulbs (at least that is what the cardboard sleeve said): (e.g. http://www.amazon.com/Sylvania-24477.../dp/B000BO5A1Y) Color/Finish: Daylight Color Temperature: 6,500K Average Lifetime: 20000 hours Lumens (light output): 2180 CRI: 88 But when I took them out of the cardboard sleeve, one of them was actually a 3400K 4' T12 aquarium/terraium/grow bulb (e.g. http://www.amazon.com/Sylvania-24671.../dp/B000M2TX22) Color Temperature: 3,400K Average Lifetime: 20000 hours Lumens (light output): 1700 CRI: 89 At first I wasn't pleased, but then I thought the mix of 6500K light and 3400K light might not be a bad thing. Any thoughts on these two bulbs for seedlings? Compared to just two 6500K bulbs?