Does anyone have knowledge on what the difference between T5, T8 and T12 lights are?
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juanitos said:T8 is the best value. T5 is the better light but more expensive. t12 is old crap.
different size
different lumens
different power consumption
This is a great chart!. I am using the T5HO currently but have been using for the third year now and I think its time to replace even though I am around 10,000 hours if not over. I have to imagine the lumens are a lot less being in the 3rd year.
Maybe I will continue to use. I just figured after 3 year it probably lost around half!juanitos said:they are pretty efficient actually. only lose a bit.
Which brands are better than others? I bought some Phillips T8s cause they're the first thing I saw at Home Depot. I think they might have had GE as well
That's because they degrade over time. I once bought some new TL fixtures with cheap TLs. 3 out of 12 tubes were broken upon receipt.. so I went online and bought 4 replacements (3 + one spare). The same colour, the same lumen (only off by 100 lumen). From the eye they both burned very white and bright. There was barely a difference in color, you couldn't notice which bulb was where when working in the room.
After two years of very unfrequent use (not more than 500 hours, they were used as attic, storage and garage lamps) you could already see that the premium lamps (OSRAM) were still white where the cheap ones appeared to become yellowish. It was so bad that I ended up switching the good ones to the storage shed (only 2 dual fixtures there.. so with the 4 white lamps) because when working om my desk I had whitish light and yellow light. When I removed the white ones to the other room, the old ones looked just as white again (for the eye).
People tend to forget that a lot of light sources tend to lose some of there lumen output, change their colour spectrum etc. I won't say that it will make a huge difference in plant growth, but why buy a cheap lamp for $3 when you have a premium one for $5? TL isn't that expensive at all.
Also the premium ones tend to have a "plus" variant with higher lumen output for an additional few bucks.
After two years of very unfrequent use (not more than 500 hours, they were used as attic, storage and garage lamps) you could already see that the premium lamps (OSRAM) were still white where the cheap ones appeared to become yellowish. It was so bad that I ended up switching the good ones to the storage shed (only 2 dual fixtures there.. so with the 4 white lamps) because when working om my desk I had whitish light and yellow light. When I removed the white ones to the other room, the old ones looked just as white again (for the eye).
People tend to forget that a lot of light sources tend to lose some of there lumen output, change their colour spectrum etc. I won't say that it will make a huge difference in plant growth, but why buy a cheap lamp for $3 when you have a premium one for $5? TL isn't that expensive at all.
Also the premium ones tend to have a "plus" variant with higher lumen output for an additional few bucks.
juanitos said:T8 is the best value. T5 is the better light but more expensive. t12 is old crap.
different size
different lumens
different power consumption
Could you possibly point me to the source of the table? It is quite good but the spectrum information is inaccurate. "White" is normally made by blending tri-phosphors so spectrally should have r, g, b peaks just like T5. There is certainly nothing stopping any phosphor blend being used in any lamp.
me lol. sorryRobisburning said:
i said this because i can find t5 that are colored, colored t8s i found are just sleved white lights. I'm wrong ofc, as i'm pretty sure i've seen blacklight t8s. but anyway, the point of the table was more to compare the lumens per watt of the lamps. ignore the spectrum part lol.
Some use different phosphors than in the white lamps to get specialty colors, like black lights, tanning beds etc..
What are the differences between 6500k 4100k etc
twilliams386 said:
CRT's (old school tv's) work on the basis of exciting phosphors. Essentially there are 3 phosphors; red, green and blue and you can make different colors by varying the amount each phosphor is excited i.e. all of them is white, none is black and any one alone is a primary color. Of course any combination of the above can be used to create any color within the colorspace "triangle" bound by the three primary phosphors.
A fluorescent lamp is not able to be addressed in the way a tv can be so whatever blend of phosphors you use is the color it produces. The numerical value i.e. 6500k is the color produced by a black body at that temperature. 6500k is an interesting one as the surface of the sun is 6500 kelvin (k) and it is a black body irrandient hence 6500k is sunlight color. 4100k is a less hot body and as such more red. 7800k is hotter and more bluey white. A good way to picture it is the colors iron goes through as it is heated in a forge.
In the image the black curve is a map of what color a given temperature would be. 1500 degrees kelvin on the far right is very red. 5500 to 7000k is essentially white and 10000k and up is blue on the left. If I were decorating house I might want 3500k "warm" colors in my lounge. From the perspective of making bulbs if I get an order for 3500k I literally just put a bit more red in the phosphor mix. 8500k, a little more blue.
Unfortunately for growers a color temp in kelvin provides limited information. We really want to know what exact wavelengths are output which means we need spectral data. What we want to do is match the absorption spectra of the leaves/chlorophyll with with output of the lamps.
I hope that helps explain, Feel free to ask if I can clarify anything.
I haven't really seen any online that are worth it if you include shipping. I also didn't want to order bulbs online thinking they would be too fragile
I just bought the 4' 2 bulb t8 shoplight with the diamond plating for 20 from home depot, then a 2 pk of Phillips 6500k t8 for 10. Its extremely bright, hoping it works til plant out. Gonna go back to get extra chain and pvc to build the stand, that'll come to about 20 or so.
This is my first year starting chiles from seeds. Every year previous I've bought seedlings from CCN. I read a bunch of articles on lighting, got my shelves together, soil and trays bought and then I saw prices on t5s. Wow. I had no idea the price, blew my mind. Needing 10 light fixtures, 2 per shelf, would cost me much more than I want to spend on some lights just to start seeds indoors for a couple of months. At first I was really disappointed because I had convinced myself that I had to have t5 in order to have a successful grow because all the articles said t5. Finally figured before there were t5 and t8 people used regular old t12 shop lights which worked so I should be ok without t5. I did find some t8 fixtures at Walmart (yeah I know) and picked up ten t8 4' 2 bulb fixtures for $10.87 each and ten 2 pks of Phillips t8 6500k bulbs for about $8 each. Now if I were doing an indoor grow completely then yeah I would probably need t5. We'll see how it goes or grows I guess, hopefully all grows well.
Thanks for all the above info juanitos and robisburning.
Thanks for all the above info juanitos and robisburning.