Maineman posted: "As an experiment, I loaded one shoplight with warm whites and another shoplight with cool whites and hung the two shoplights over two 11" x 22" trays of emerging seedlings. The trays were lined up the long way on the 18" x 48" shelf with the 48-inch fixtures, so that half of each tray had cool whites directly over it and the other half had warm whites over it. All of the plants were under one fixture or the other. The objective of this experiment was to see if the plants grew faster under the cool whites or the warm whites or a mix of the two. To my surprise, there wasn't a significant difference in growth rates, but the plants under the warm whites all leaned strongly toward the cool whites and the plants under the cool whites grew straight up with no attraction at all to the warm whites or a mixture. So I decided that if the plants preferred the cool whites so much, that I wouldn't spend any more money buying the more expensive warm whites." Ah, it's not that the plants PREFER the cool white light, as the plant hormones in the leaves orient themselves toward the sun solely via blue light. You can grow plants under red light alone and get adequate growth. Red light is needed for growth. But the plants will probably think they're growing in shade without a source of blue light. The cool white lights have much more blue light, so the plants will actually turn away from the valuable source of red light in the warm white tubes to focus on the cool white tubes. Now, you can grow plants only under blue light, as it has more energy per photon than red light does. But the plants need red light too for flowering. Another thing to remember is that when a plant doesn't get enough light it will usually grow faster in the attempt to get closer to the light source. This causes spindly growth and weak stems. So faster growth isn't always better. *********** Another interesting thing about sunlight: bright sunlight is way MORE light than plants can use. Hard to believe? Well, consider this. Plants germinate in low light conditions, in the Spring. And they do fine with shorter days and less intense sunlight. And the plants flower and come to harvest AFTER the solar peak of the year, in late summer and Fall. So photosynthesis is rigged to work well at LOW light levels. When sunlight gets REALLY bright the chlorophyll platelets would be taking in so much energy they'd oxidize and break down. So they have a trick to deal with the varying light levels. The Chlorophyll platelets come in "stacks". These stacks spread out in low light so all of them are on-line and collecting sunlight. But in bright light, they'd over-rev. So the stack retracts, and the platelets line up vertically. Now only the top platelet is exposed to sunlight. The others are in the shade, protected and off-line. Also, there's a chemical mechanism that helps off-load the excess energy during peak light conditions. So we don't NEED to duplicate the June/July sunlight. We only need to duplicate the sunlight in late March. And then, the peak absorption spectra for chlorophyll is in the blue and red wavelengths, so if we focus all our light there, we can grow flowering plants in about 15 watts per square foot worth of LED's. Ignore the yellow light, that the human eye is most sensitive too. Skip the green, that the plants can barely use anyway. It may look weak, but it should work. I'm going to get one of those 168 LED blue/red lights for my windowsill. I have a Red Robin that's about three years old now, all together. It grew too fast in February and the supplemental light may solve the problem.

That is my question, HU-773166389. My late husband, deceased 9 years now, built a brick will with 6 pillars and wired 2 for lighting along with landscape lighting. Sadly he passed before completing everything. I purchased limestone caps and 120v pillar lighting fixtures a couple of years ago but just located a brick layer pointer who will place the caps. He noticed that the wiring is LV in the pillars. As he revisited it, I recalled the questions that I had when I originally purchased the fixtures. I would want to use LV-LED bulbs anyway. Nothing is wired into the breaker box yet, but to run new wire would be a major investment as there are brick walkways that run from the house to the the where the pillars are. I am hoping from reading this that I will be able to have the electrician wire the 120 fixture directly to the 12 volt landscape wire that ia wired to a transformer and install a 4-10 watt bulb in each. and be done. Just need confirmation.

I'm looking for lighting that i can use in a subtle way to mimic flickering candles. I was thinking I might make or buy small wooden lanterns, or stone/concrete japanese-style lanterns and install wired lights that mimic candlelight. I'm considering low-voltage because I could put the lights on a timer or photocell, and incorporate them into a plan that might also have some non-candle-type lights in a few areas. I have considered solar,but our winters don't provide much light. All the solar lights I see around my neighborhood don't last more than a few hours, and are the wrong color for a candle-light effect. Most solar and LED lights I've seen have a subtle blue hue, even though they're labeled as white. I have nothing against those lights, but I don't think it's what I'm looking for to solve my design dilemma. Any suggestions? Ideally, I think I'm looking for something close to the battery powered ones I've linked below. PS: I hope you won't mind that I cross posted this on the gardening side. I'm hoping to get perspective from what I believe are two likely very different groups of readers. Here is a link that might be useful: battery powered candle-like lights

I have a LOT of low voltage lighting in front of our house, the wattage we're using varies from 4w to 20w. Even a 4w fixture puts off enough light to cast a decent glow on a sidewalk, but we use those mainly for aesthetics rather than lighting. The 20w uplights are halogens and are incredibly bright, they light up the front of the house nearly as well as 150w floods. We also have some 8w and 11w fixtures lighting certain sidewalk areas. When you get into a bunch of lighting like I have it does become a maintenance issue, I'm out there about once a month changing a few bulbs. So make sure you go with fixtures that you can get into easily enough, and that you mount them in places that you have easy access to. Solar lighting is getting better, but it's not quite there yet. They're starting to use more LEDs in them and that helps. LEDs use a lot less juice and therefore the lights stay on longer. But they add cost too. We have 6 tiki LED solar lights around the pool. They have an awesome candle-like flicker effect. They don't put out much light though. During the summer they stay on all night. In the winter they don't charge as much and only stay on a couple of hours. Another option that is fairly new is line voltage LED lighting. It's very efficient and the line voltage means you don't need a transformer, and the fixtures can be daisy-chained. The ones I've seen weren't very bright, but I'm sure this will improve. This could be a good trend in the future because LEDs have a long, long life and the elimination of a transformer is a money-saver.