light question

[orchid-man]

you might as well go to the T12 floro'3 they are cheaper last as long and they come in a range of colors .If you can get the fittings with electronic controll gear in them they generate even less heat than normal.

The first thing that has to be consudered is the light level that is required to grow and flower the plants.My main growing at this time was measuring 3500 lux
or 48 f/c .Under these levels I am able to grow and flower Cats,aand their alliance ,oncids along with their relatives and also Aussie Dendrobs and not to forget Phallies when the temp is warm enough and paphs .
Wonce you have deteminded the light levels required it is then a matter of getting that level.
A 3ft floro tube which is 17.5 inches above the plants has a light level of 2600 lux or 250f/c.These figers are for a brand new T12 tube and within 6months of operation at 12 hours per day will be 1/2ed.This is a natural happening and all floro tubes and the compact floro lamps do this (you can not get away from it).The tube mentioned above is a Philips ,lifemax,TLD30w/840 coolwhite.The Tube that I have listed above is a high output lamp and puts out about 1/3 more light than the standard floro tube.
Here in NZ this tube is now the standard and use everywhere ,it puts out a pinkish light to the naked eye but if two tubes were to be used side by side I would make the 2nd tube a TLD 30w/860 as this gives a very very white look, as use in shop signs.This combination would increase the light temperature a more aproperated level.In fact most aquatic plants can be grown just under the 30w/840 lamps,even to a depth of 14inches.

[p 1]

Ok, cool, thanks for the advice

i was planning on reading all about these lights today, but then i woke up sick, and now i feel terrible.. blech..

[jtlqh]

I burned my catt seedlings by placing them too close (around 6") to the 4 36" T12 tubes. These tubes are pretty strong. I put my Tolumnias 2" away from the light, and they are sending out spike.

[Tindomul1of9]

Feel Better P1,

Is there anyway for us at home to measure lumen output?? I want to find out what my different setups give off.
THanks for the info.
Uo until I bought the power compacts, I had been using regular t-8's, the type you buy for aquariums. The whole time I was always looking for better and brighter t-8's. So they aren't all the same. Some are dimmer than others.

[Tindomul1of9]

I found this table that compares Lumens output between the different types of lights available out there. Hope this helps!


Oki dokie,

If I go by the chart above which says (for me that is), that a Power Compact light has 4800lm(lumens) per 55 watts.
Then Seeing as how my setup has 2 65 watt Power Compact bulbs, that would mean that my setup is putting out 11,345.5 lumens of light.
4800lm/55 watts = X lumens/130 watts(two 65 watt bulbs)
cross multiply, 624,000 lm watts = 55 watts X
Divide by both sides,
X = 11,345.4555555

I hope people agree with my math here

[Diane]

Oh, dear! This is going to bring up the whole lumens, footcandles, color thing again, isn't it??? I know there is a thread somewhere, but I can't seem to find it. It explains the conversion of footcandles to lumens, I think there is a thread on how many lumens/footcandles are needed for various orchids, too.

BD????

[Tindomul1of9]

That would be soo cool. But for now, I gots to get back to work!!

[p 1]

i think it would be 4128lm/55watts, not 4800, though. "mean" is the arithmatic average, i think the chart is saying that the initial output for a brand new bulb is 4800lms, but that the average output, once the new-ness wears off is more like 4128lm. which makes sence with the next column, because 4128/55 = 75% efficiency. in that case, (4128*130)/55 = 9757.0909 repeating. personally, i would say "around 10k lumens" and consider it good enough. ;P

the weird thing, to me, is that neither of the lights i was looking at fit that chart. one says it has 12000lm/125watts (=98% efficency) which seems high and the other one has 7900lm/150watts (=52.7% efficency) which seems high. also, i have no idea what the "k" number in the light descriptions is, like "150W 6500K 7900 Lumens."

jeeze, this post took like half an hour...i would be in bed, but i saw my catt is losing another leaf because it doesn't have enough light, and it brought me back here..

EDIT: heh, neither of those posts were there when i started! :P

footcandle = 1 lumen per square foot. so the more lumens, the moore FCs, and also the close to the bulb the more FCs. as for light per orchid, according the the AOS pdf, catts (for example) like around 5k FCs, which should be providable with either a 7.9k lm or a 12k lm light, hung at different distances. from what i've read here, it seems like catts want as much light as they can get without getting scorched, though. all i know is mine is not getting enough.

[Tindomul1of9]

Im not sure, but I think K stands for Kelvin(how that relates to light, I have no idea, I'm probably dead wrong).
I find it hard to believe that any light source has a 98% efficiency rate, as that would mean almost no energy is lost to heat. Correct me on that one orchidman!
I was calculating the 4800 becuase my lights are only a few weeks old. Thanks for the info on the Catts though. I wonder if I can grow a Sophornitis cernua under those lights??????

[Diane]

The 'k' relates to the color spectrum of the light. High value, such as 6500 is good for growth, lower value, like 2700 is good for blooming. It is the range within the light color spectrum that that particular bulb produces.