These are photos taken on 5/5/2015 after I removed the plants from my fluorescent light growth chamber on the previous day:

The right row were the daylight controls; the rest are from the growth chamber. Incidentally, the polycarbonate panels on the right are new whereas the ones reported at http://forums.gardenweb.com/discussions/2005610/how-to-easily-supplement-fluorescent-with-incandescent-light were about 25 years old, i.e., I now have more daylight. The only variety with the curled up leaves is New Girl from the growth chamber. The daylight grown New Girl are without curled leaves and are the tallest in the right row. Otherwise, the varieties are Big Zac, Better Boy and Best Boy.

My only conclusion is that I was able to salvage the plants from the failed LED strip lighting experiment.

Using PC power supply(especialy old one) for any LEDs is fattal error. Efficiency of LEDs drops resolutely- can be only few % of the values of luminious flux. Test voltage by potentiometr. Redo by serius stabil LED power supply 180W min.

kotbogomot, you are wrong in so many ways.

"potentiometr" is not for testing voltages; a potentiometer is a mechanically variable resistor. Before starting this thread, I tested the voltages using a digital multimeter.

Just now, I checked the ratings of my old computer power supply and it is 16A at 12V or 192 watts whereas the current requirements for all of the strips are less than 12A. Also, before starting this thread, I connected just one 48" strip to the PC power supply and another power supply and the resulting brightnesses of the individual strip was the same as when operated in parallel to all the other strips.

The fundamental problem of today's LED strip lighting is that the strips incorporate current limiting resistors that severely waste electric power. That may change in the future, if manufacturers can inexpensively incorporate current limiting transistor circuitry onto the strips. But, right now, these strips are only good for decoration.

Ok. Iam not good in english, srry. But i had same problem and now with new power supply iam doing pretty well. Its voltmetr :) one archaic : http://www.wikiskripta.eu/index.php/M%C4%9B%C5%99en%C3%AD_nap%C4%9Bt%C3%AD

U have to check voltage under load. Iam using 5630 chips and voltage drop under load was neraly 3V(9,2V) at the end of 1m strip(60pcs) with PC power supply.

Also checking brightness on blue and red color by eyes is inadequate. Only way is to check volatge on various places under load- everywhere should be 12V or by luxmetr.

PC power supply is not good for 12V stabil current consumption. 12V is not main branch of PC power supply and is restricted often.

Further more -not waterproof strips are better(luminious flux,durability) and also quality of LED chips may be diffrent.

Mayby you are unlucky with quality of yours chips. But it realy works in my case.

Exactly what brand and model of LED strip lights did you buy and what did you compare it with? Why don't you post your own thread and give all of the details like I did?

In my case, the brightness to my eyes and the plant growth results from 140 watts of LED strip lighting were much, much less, maybe, 90% less, than from 200 watts of red and blue fluorescent lighting.

"voltage drop under load was neraly 3V(9,2V) at the end of 1m strip(60pcs)"

I forgot to mention that you are supposed to connect the power supply to both ends of the strip sections (like I did). That way, there are no voltage drops at the ends but, instead, half of what you measured at the middle of the strip. I mention this because it is not too late for you to correct this mistake.

This post gets very interesting,enjoy reading this kind of product development.

I was at Best-buy and they have powersupplies for pc's 400 watt for $29.00

I think you can get 12v, 24V and even 48V power supplies at Ebay for a good price too see link

http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&LH_BIN=1&_nkw=Switch%20Power%20Supply%20Driver%20adapter%20AC110%7E220V%20TO%20DC%205V%2012V%2024V%2048V&rt=nc&LH_FS=1&_trksid=p2045573.m1684

Working together with adjustable up or down convertors you can build a nice setup.

This really helped me out! I was totally about to start running my led strips near my house plants at night to give them some extra light in the apartment since I like to keep my sun shades down.... Good to know that it probably wouldn't be worth the extra electricity.

I'll throw in my own two cents here.

For starting seeds, I use T8 strips. I have 4 tube fixtures above each of my seed starting shelves, and I use 2 cool white (~4100K), 1 warm white (2700K-3000K and 1 daylight (6500K) in each fixture. I don't have pictures, but my seed starts under these lights look about the same as seedlings started in full sunlight. Seedlings need a much more balanced spectrum of light, and conventional white lamps seem to very work well for sprouting seedlings and in the early stages of growth.

The red/blue lights are often misunderstood, and most of the ones on the market have a "mix" that is tailored for growing "medical flowers" from established plants. In that environment, blooms = $$$$, so those lights are made to stimulate blooming with a lot of red light. You don't want to stimulate seedlings to bloom immediately, so red light is not what you really want to put on seedling starts.

Looking at aruzinsky's setup, I see 11:1 red:blue. That's really pushing it even for established plants, and not what seedlings really need at all.

For established tomato and pepper plants, the red/blue (3:1 or maybe 4:1 red:blue) LED "grow lights" work great. You'll get prolific production from those lights as they really stimulate blooming and fruiting. Just be sure you're fertilizing regimen is adequate for the production you're demanding from the plants. Using the LED "grow lights," I got more cherry and Roma tomatoes per plant from my "basement tomatoes" last winter than from the plants in my garden over the summer.

There are some kinds of plants (leafy herbs like basil and cilantro, and woody herbs like sage and rosemary) that you don't want to stimulate to bloom. Those plants benefit from a lot more blue light after they are established. Blue light stimulates leafy growth. The "blurple" LED strips or lights with 3:1 or more red:blue LED's will make cilantro and basil bolt and bloom quickly, without producing much tasty foliage. I'll be experimenting this coming winter with all blue or blue/white(/deep red) LED lighting for my leafy and woody herbs. This comes after a year of failure using the red/blue lights with a high red:blue ratio last year. I had some of my woody herbs die from lack of (proper) light, and my leafy herbs bolted/bloomed early and failed to produce much foliage with the very red "LED grow lights."