Is your window obstructed in any way? Southern window has the highest light of any window (in the northern hemisphere anyways). You're lucky to have that as your starting point. I've grown catts, phals, and any number of other plants in a south window without supplementation for a number of years and they all bloom nicely. So I would think, without being able to see the light intensity for myself, that a south window with supplemental lighting would definitely be enough.

Well... 1. I live on the third floor of an apartment complex. 2. the windows are tinted. 3. there is an overhang of a foot or too, and I feel like the sun is too high to be of any use. 4. The windowsill, being southern, gets about 20 degrees hotter than the ambient temp. Its the middle of March and I've already recorded 102 degrees. 5. finally, I've run out of room on the window sill, thus I've had to get creative.

No light is truly a waste of money but some are better values than others. I just bought a couple of 40W CFL lights today. They are off brands but I paid $14.99 each for them. I think I could have done a little better by buying in a discount store but I still did better than you I think. Why. Because my lights give me 2465 lumens just like yours but mine will fit into a standard clamp on fixture ($6.99). And I can hang the light high and light several plants with an average light intensity or bring it in close and really zap something that needs more than average intensity. With tubes even touching the plants you can't ever get more than average intensity the wide tubes spread the light out whether you want to or not. And 24" tubes and fixtures and terribly expensive as they are an odd size that are usually only used for the aquarium trade.

What temperature are you measuring if not the ambient? Its the ambient that matters. Since you have the light you may as well use it but IMO tube rigs do not work well in windows. If possible you want to angle it so it does not block sunlight coming in. This early in the year there should still be good sunlight till close to Noon and soon after 3:00 in a true South window. I have seen some people set up tubes so they stand vertically and fire in from the sides. That's fine if you have really narrow windows H

I'm about to teach an orchid workshop for our store and was planning to recommend four 4' tubes if people wanted to culture phals and paphs, or Farmtek's 125 watt CFL in a light hood if they needed more light in less space. Whaddya think of that, Howard?

Howard will say its not enough light. And he will probably be right, depending on the plant.

I had a double four foot thing going at my former house but it had a great, huge, south window with little overhang and no shade and I got wicked light...but I still ended up adding a third fixture eventually for six bulbs total. Then I added some spotlights on the side that didn't get window light.

Now I'm back to using two fixtures but I use better spotlights and the plants are closer to them and most importantly, I'm growing more shade loving species.

In closing, you should move to a house where you can grow outside. In Austin you could probably grow all that stuff and more outside for all but maybe a couple months of the year.
Boomer Sooner!
-MB

You are too funny MB. Actually Holly, I wouldn't recommend tubes at all, just various sizes of CFL depending on the type and number of plants that the customer was planning to grow. Four tubes is 144W (used to be 160W) and covers 48 linear inches whether you actually need that much space lighted or not. For just a few low light orchids a single 23W can work or a 36W for a little more oomph. For slightly needier plants there are 40W and 45W. Then as you know there are the 85W, 105W, 125W and higher lamps for either very light hungry orchids or larger numbers of medium light ones. I think tubes are destined to go the way of incandescent lightbulbs for plant growing. And I am not really sure about the premium reflector. You might leave it to the customer. I was shocked to learn that the bare 125W bulb in the Farmtek light was only $37.00 but the combo of lamp and reflector was, I can't rembember exactly now, but certainly over $90.00! Farmtek is though the best source for these lights I have seen, the next cheapest source wants $139.00 for the same light.

H

Anyone have any ideas what I could attach a clamp light to, so it shines above my plants? I know you are all a creative bunch, and am trying to come up with ideas. I bought one Wonderlite on a clamp and there's nothing to clamp it to. Plants are on 3ft tables and there's nothing nearby to clamp to. Ceiling is too high - 18ft.

Jane

18' ceilings... [envy] I'll let someone less petty help you with your problem Ms. 18' ceilings. LOL. Hmmm. Interesting, does the solution have to be aesthetic? Pendant is always correct IMO. Too high? Nah. I was in a church couple of weeks ago and they had microphones hanging from what must have been 30' cable's, very cool looking. Getting up to the ceiling to attach the vertical leg of lamp cord will be your challenge but you only have to do it (or have it done) once. Or you could get one of those short clothes racks like the better hotels use to push your hangable accessories. Maybe a double wide if you plan on mounting two lights. I consider that last, still in the realm of aesthetic. Ugly but functional? A 5' tall stepladder.

H

I use many of the clamp-on style lamps. Two of them I simply have as hanging lamps (I just removed the clap on device). Over a table could you simply use one of the decorative arms sold to use with regular garden hanging bnaskets? Or purchase decorative chain and hook to hang from the ceiling.........18' WOW, lots of chain. LOL. Good luck!

Thanks, actually Howard, I was toying with the clothes rack, kinda thingy. I was also thinking about what photographers use to hold lights. Don't they use something which telescopes? These ceiling are a nightmare. You should see us trying to change the light bulbs. We use CFL type because they last for years, but they are not the greatest from that height. We use table lamps. The room is like a open loft. All windows on one whole wall. I use octopus type floor lamps for some of the plants, but my larger plants are too tall for the floor lamps. Everything is making growths or sheaths and I want them to grow upward, not toward the windows (sideways).
If anyone knows of a pole-type thing, which telescopes, please let me know. I hate wasting a good bulb.

Jane

Jane, I've used the cheap hanging-basket-arms, screwed into the molding around the windows, to hang single pendant reflectors (HD, $10, clamps removed), just as granniek mentioned. I also seem to remember that Kevin in MN had made something neat using two of these arms, and then a piece of 1" PVC pipe cut to lay across them. Lights were hung from the pipe, sort of like a drapery rod, but projected away from the wall. Of course, if your wall is really all glass, maybe there's nothing to screw into!

Mine are clamped to drapery rods hung a little above the middle of the windows, and two are attached to rod holders screwed to a hutch type piece of furniture. Actually doesn't look too bad.

I haven't figured out how to put any in the kitchen windows (nowhere to screw supports in the middle of the window.

When I bought the wonderlites, I assumed they came on those swivel arm things, and was disappointed when I found they didn't.

good luck finding what you need!

This is my living room. Poor photo, but gives an idea. Except for the wall near the fireplace, there are no electrical outlets. The ceiling from the windows, goes up 18ft. I can't string cords all over the windows and ceiling, or I'll be divorced. As it is, there are extension cords all over the floor to run a bunch of floor lamps for the plants.There are shades above the windows which are too flimsy to attach a clamp to. The room runs about 30 ft long. You can barely see the sitting area. The couch and chairs are surrounded by tables with plants. I have an understanding family. I don't want to push it....
{{gwi:153995}}

Does anyone know of where I can get the action spectrum (the different intensities of different wavelengths given by a particular bulb) of common fluorescent lights and CFL's. Because, sure it's fun to have a cagillion cagillion watts shining on the plants, but how much of it can they actually use? Plants only "see" and use the ends of the spectrum, all the energy given off as green and yellow light is a waste. This might just be a nitpicky deatil but I'm curious to see if such a report exists.

I see them from time to time. Look around at some hydroponics type websites and find the lamp manufacturers websites. I don't know of what use such information is however because at the end of the day you still have to buy something and that something is pretty much going to be a 'daylight' spectrum CFL or Warm or Cool spectrum or possibly 'Daylight' tube. None of them have wonderful spectra from a plant growth standpoint as all of them are optimized for human vision i.e. heavy emphasis on the green/yellow wavelengths. The early Gro-Lux tubes and even the later Gro-Lux Deluxe and Wide Spectrum lamps were miserable failures. They cut out the 'non-essential' green and yellow light and concentrated on the blue-red but results were no improvement on what standard tubes could deliver despite the high cost of the specialty tubes. So now you will only find plant growth tubes in aquarium shops and they are standard daylight spectrum tubes very heavy in the green/yellow with modest representation in the blue and red. They work. Why? Because if you throw a cagillion watts of light, any kind of light at a plant, it will grow. So spectrum, schmectrum. Lumens, my friend, look for the bulb with the highest number of lumens and call it good.

H

You can bop on over to the Growing Under Lights forum for more discussion on PAR, spectrum, photosynthetic pigment absorption bands, etc that you can shake a stick at. Approaches holy war levels in some threads. You'll also occasionally find some nifty ideas on wiring/adapting fixtures for greater light output (so called "overdriven" fluorescent fixtures). I tend to agree with Howard that given the choice between an ideal (or idealized) output spectrum and more lumens, I'll choose the latter.

Hi guys! I am more of an indoor herb grower, and I don't mean 4" potted herbs either! :) I am in a position where I have 2 large south facing windows (3'tallx109"wide) with plants, in totes along the floor. Because of there hight they are at a great place to use natural light, what we get of it anyway. Being that we are getting towards fall, or close enough for me to be thinking about, I want to add some lights to help everything going as much as possible. When my annuals fail I will just pull them and grow more salad related plants which should do ok. Also once we get into winter I will pretty much just use light bulb power since Vancouver BC gets a pathetically little light. In the mean time here are a few things I have been trying to work out and seem to be relevant. If anyone has any insight I'd love to hear from them!!

1 - It has been thumped into my head that lumens are great but that is only part if the issue. High power halogen bulbs wouldn't benefit our plants at all. Having seen people post in the growing under lights forum plenty of spectral analysis it seems that the grow bulbs are sort of a diminishing return. If you want flowering plants basic cool white bulbs have the most red light and are great, daylight have more blue and will help most with vegetative growth. The ubber priced grow bulbs ($30 a bulb Vs $4 for a daylight bulb) aren't worth the cost, especially if you can reinvest that money in more plants and lights or your energy bill!! :)

2 - Inverse square law - Simply stated the farther your plant is from the light the less good it does you. There was some argument about how relevant these numbers might be with all the other concerns but it does demonstrate the principle... A 48", 32W (T8)6500K daylight bulb puts out 3000+ fc at 0", at 3" it is 1500fc and at 12" it is 500fc. So as much reflectors and the right fixture, placement is key!!

So my main issue at the moment is trying to balance natural like with artificial. 2 4ft fixtures are easily affordable and usable however you hang those a few inches off the plants and you are really pretty much growing with only artificial light since the fixtures will shadow the plant, at least with my current arrangement...

What exactly is your question Farmer Bob? And BTW the inverse square law does not apply to 4ft tubes which behave like 'line sources' (falloff is linear). But even linear falloff is too rapid to be casual about when the intensity at the peak (6" below tubes) cannot be more than ~1000fc.

H