Like all well educated people, you forget about us ignorant folk following along
The 6,500K and 5,000K probably give off more blue then the 4,100K, but for the reasons above no one knows for sure. The only way to check this is to get a print out of the spectrums emitted and the their power.
and then Tula states:
What are the most important aspects of a plant-growing bulb?
My contention is that it is spectral output and intensity. I don't know if you agree or not.
Now, summarize your discussion and give us the punch line, to get a good bulb, I need to get a print out of the spectral output and look for peaks (or are moutains better?) in the red and blue.
I checked and the one bulb I thought was 5000K is actually a TL841/ALTO 25 4100K that puts out 2225 lumens and has a CRI of 86
I cannot find any info on the spectral output... now as I understand it, this bulb may not be useful as I have no idea how much red or blue I am actually putting over the plants, right?
How do I find out (I.e. what terminology exists) for red or blue peaks?
thanks in advance _________________ "Just don't look in my fish room honey... it's just better for all of us. "
In truth, lumen output (intensity, in simpler terms) is more important than spectral output, and perhaps it was confusing to have listed them in the reverse order. More often than not, issues of too low an intensity of lighting are remedied not by exchanging the lamp for one with a higher output, but by increasing the total number of lamps used in the setup. In other words, if you have 2-3wpg over your tank, generally this should be enough to grow most plants you desire, almost irrespective of the lamp used (almost...). Lumen ratings are more readily available than spectral output graphs, so you can use these to 'maximize' your lighting situation if it's of borderline overall intensity.
However, IMO you can go on and on hunting for ever higher lumen ratings, but at some point the returns on your efforts just won't be worth it. With that in mind, you can simplify the whole process by looking for bulbs designated as 'daylight,' 'full-spectrum,' or 'trichromatic/triphosphor'. While this is as inexact a science as how manufacturers get their color ratings, for the most part such bulbs will feature mostly favorable and balanced spectra for better plant growth. After that, you can experiment with other lamps to see how they affect aesthetics or plant growth, but at least a few weeks of observation should transpire before a verdict is made. I take color temperature into consideration when I look for a bulb, but only as a very rough guide as to what kind of cast it might produce over the tank (see here for a visual reference), never as a predictor of how much better or worse it might grow plants compared to another bulb. For all the numbers-crunching that technophiles like to do with various lamp parameters, my personal experience suggests that the resultant theories are mostly unsupported by real-world applications of them. _________________
In truth, lumen output (intensity, in simpler terms) is more important than spectral output, and perhaps it was confusing to have listed them in the reverse order. More often than not, issues of too low an intensity of lighting are remedied not by exchanging the lamp for one with a higher output, but by increasing the total number of lamps used in the setup.
Amen. I had been wanting to jump to the fray with these summary type statements, but we've known each other long enough...I knew you'd get to the the "real world" type answers without me interfering. However, getting to this point was extremely illuminating...(sick pun)
For all the numbers-crunching that technophiles like to do with various lamp parameters, my personal experience suggests that the resultant theories are mostly unsupported by real-world applications of them.
Agreed. Though when one shakes the tree long enough some additional fruit does fall. With careful testing the enthusiast can elicit different growth behavior by tweaking the combinations of bulbs. But without question most people simply need to make sure they have enough light (watts and lumen's as a reference) directed properly into the tank that is then balanced against the available CO2 and nutrients. It's really no more complicated than that.
Superb info my friend, a keeper for our The Best of Forum.
With me, Steve, later's a safer bet than sooner...
And I completely concur: While the numbers-crunching thus far has, IMO, yielded little of concrete value, I no less laud such efforts and suspect that someone's work someday will bear more tangible...um...fruit. _________________
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