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all lumens created equal?
I was in WalMart today getting some replacement bulbs - I use 4 2'
flourescent bulbs for one set of plants - when I noticed lumen output varied widely between bulbs. Aquarium/Plant bulbs had 750, Home and Bath bulbs had 1250. And for the same space, I could get 3 or 4 times as many lumens with compact flourescents - the circular halo-looking things. All at 20 W apiece. More lumens means more light, right? Is spectrum a factor, or for the same price why wouldn't I just go for the highest lumen count for the space? What am I missing? |
mg queried thusly:
I was in WalMart today getting some replacement bulbs - I use 4 2' flourescent bulbs for one set of plants - when I noticed lumen output varied widely between bulbs. Aquarium/Plant bulbs had 750, Home and Bath bulbs had 1250. And for the same space, I could get 3 or 4 times as many lumens with compact flourescents - the circular halo-looking things. All at 20 W apiece. More lumens means more light, right? Is spectrum a factor, or for the same price why wouldn't I just go for the highest lumen count for the space? What am I missing? Intensity is certainly one factor, and it becomes important with plants that demand a lot of light. However, another factor is photosynthetically active radiation (PAR), which is light that plants can absorb and use. A good web page on the whole subject is he http://www.aquabotanic.com/lightcompare.htm There's an interesting table about 3/5 of the way down on PUR efficiency ratio in uE/s/watt that should be kept in mind when comparing "Gro-Lux" to regular fluorescent tubes. They really aren't worth the extra expense. The e-mail address in the header doesn't work. Send no mail there. -AJHicks Chandler, AZ |
"Aaron Hicks" wrote in message ... mg queried thusly: I was in WalMart today getting some replacement bulbs - I use 4 2' flourescent bulbs for one set of plants - when I noticed lumen output varied widely between bulbs. Aquarium/Plant bulbs had 750, Home and Bath bulbs had 1250. And for the same space, I could get 3 or 4 times as many lumens with compact flourescents - the circular halo-looking things. All at 20 W apiece. More lumens means more light, right? Is spectrum a factor, or for the same price why wouldn't I just go for the highest lumen count for the space? What am I missing? Intensity is certainly one factor, and it becomes important with plants that demand a lot of light. However, another factor is photosynthetically active radiation (PAR), which is light that plants can absorb and use. A good web page on the whole subject is he http://www.aquabotanic.com/lightcompare.htm There's an interesting table about 3/5 of the way down on PUR efficiency ratio in uE/s/watt that should be kept in mind when comparing "Gro-Lux" to regular fluorescent tubes. They really aren't worth the extra expense. The e-mail address in the header doesn't work. Send no mail there. -AJHicks Chandler, AZ Also, when comparing output of compact fluorescent bulbs, be sure to read very carefully. Lots of them use alternative measurements to express outputs and use confusing language comparing the output of regular incandescents to CFL bulbs. I just recently purchased some CFLs rated at 3500 Lumens for an 85W bulb. I honestly doubt you can find a 20W bulb that will put out as much light as you say the packaging indicated. Sam |
"Aaron Hicks" wrote in message ... mg queried thusly: I was in WalMart today getting some replacement bulbs - I use 4 2' flourescent bulbs for one set of plants - when I noticed lumen output varied widely between bulbs. Aquarium/Plant bulbs had 750, Home and Bath bulbs had 1250. And for the same space, I could get 3 or 4 times as many lumens with compact flourescents - the circular halo-looking things. All at 20 W apiece. More lumens means more light, right? Is spectrum a factor, or for the same price why wouldn't I just go for the highest lumen count for the space? What am I missing? Intensity is certainly one factor, and it becomes important with plants that demand a lot of light. However, another factor is photosynthetically active radiation (PAR), which is light that plants can absorb and use. A good web page on the whole subject is he http://www.aquabotanic.com/lightcompare.htm There's an interesting table about 3/5 of the way down on PUR efficiency ratio in uE/s/watt that should be kept in mind when comparing "Gro-Lux" to regular fluorescent tubes. They really aren't worth the extra expense. The e-mail address in the header doesn't work. Send no mail there. -AJHicks Chandler, AZ Also, when comparing output of compact fluorescent bulbs, be sure to read very carefully. Lots of them use alternative measurements to express outputs and use confusing language comparing the output of regular incandescents to CFL bulbs. I just recently purchased some CFLs rated at 3500 Lumens for an 85W bulb. I honestly doubt you can find a 20W bulb that will put out as much light as you say the packaging indicated. Sam |
GaWd wrote: "Aaron Hicks" wrote in message ... mg queried thusly: I was in WalMart today getting some replacement bulbs - I use 4 2' flourescent bulbs for one set of plants - when I noticed lumen output varied widely between bulbs. Aquarium/Plant bulbs had 750, Home and Bath bulbs had 1250. And for the same space, I could get 3 or 4 times as many lumens with compact flourescents - the circular halo-looking things. All at 20 W apiece. More lumens means more light, right? Is spectrum a factor, or for the same price why wouldn't I just go for the highest lumen count for the space? What am I missing? Intensity is certainly one factor, and it becomes important with plants that demand a lot of light. However, another factor is photosynthetically active radiation (PAR), which is light that plants can absorb and use. A good web page on the whole subject is he http://www.aquabotanic.com/lightcompare.htm There's an interesting table about 3/5 of the way down on PUR efficiency ratio in uE/s/watt that should be kept in mind when comparing "Gro-Lux" to regular fluorescent tubes. They really aren't worth the extra expense. The e-mail address in the header doesn't work. Send no mail there. -AJHicks Chandler, AZ Also, when comparing output of compact fluorescent bulbs, be sure to read very carefully. Lots of them use alternative measurements to express outputs and use confusing language comparing the output of regular incandescents to CFL bulbs. I just recently purchased some CFLs rated at 3500 Lumens for an 85W bulb. I honestly doubt you can find a 20W bulb that will put out as much light as you say the packaging indicated. Sam Well, I guess the real question with the CFLs is what is their PAR value, now that I know lumens don't matter to plants. |
"mg" wrote in message ... GaWd wrote: "Aaron Hicks" wrote in message ... mg queried thusly: I was in WalMart today getting some replacement bulbs - I use 4 2' flourescent bulbs for one set of plants - when I noticed lumen output varied widely between bulbs. Aquarium/Plant bulbs had 750, Home and Bath bulbs had 1250. And for the same space, I could get 3 or 4 times as many lumens with compact flourescents - the circular halo-looking things. All at 20 W apiece. More lumens means more light, right? Is spectrum a factor, or for the same price why wouldn't I just go for the highest lumen count for the space? What am I missing? Intensity is certainly one factor, and it becomes important with plants that demand a lot of light. However, another factor is photosynthetically active radiation (PAR), which is light that plants can absorb and use. A good web page on the whole subject is he http://www.aquabotanic.com/lightcompare.htm There's an interesting table about 3/5 of the way down on PUR efficiency ratio in uE/s/watt that should be kept in mind when comparing "Gro-Lux" to regular fluorescent tubes. They really aren't worth the extra expense. The e-mail address in the header doesn't work. Send no mail there. -AJHicks Chandler, AZ Also, when comparing output of compact fluorescent bulbs, be sure to read very carefully. Lots of them use alternative measurements to express outputs and use confusing language comparing the output of regular incandescents to CFL bulbs. I just recently purchased some CFLs rated at 3500 Lumens for an 85W bulb. I honestly doubt you can find a 20W bulb that will put out as much light as you say the packaging indicated. Sam Well, I guess the real question with the CFLs is what is their PAR value, now that I know lumens don't matter to plants. Well, you're not going to find a PAR rating on a bulb. What you can do instead is ensure that you have purchased a bulb with the correct temperature rating-in degrees Kelvin(K), as well as have the maximum output in Lumens. A "soft"/"warm" bulb is rated around 2700-3100K, a "cool" bulb around 4100K, and a "daylight" bulb is rated at about 5500-6500K. I currently grow under a mix of Philips cool and Daylight Deluxe bulbs with really good results. I am transitioning to the Compact Fluorescent bulbs, they have a 6500K color, a high CRI, and for a CFL, a high output. Best of luck wading through all of the BS and marketing on bulbs...it's difficult for regular people like you and I to understand. Sam |
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